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Ahmad N, Sharma P, Sharma S, Singh TP. Structure of a novel form of phosphopantetheine adenylyltransferase from Klebsiella pneumoniae at 2.59 Å resolution. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2024; 53:147-157. [PMID: 38456905 DOI: 10.1007/s00249-024-01703-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/16/2024] [Accepted: 02/10/2024] [Indexed: 03/09/2024]
Abstract
Phosphopantetheine adenylyltransferase (EC. 2.7.7.3, PPAT) catalyzes the penultimate step of the multistep reaction in the coenzyme A (CoA) biosynthesis pathway. In this step, an adenylyl group from adenosine triphosphate (ATP) is transferred to 4'-phosphopantetheine (PNS) yielding 3'-dephospho-coenzyme A (dpCoA) and pyrophosphate (PPi). PPAT from strain C3 of Klebsiella pneumoniae (KpPPAT) was cloned, expressed and purified. It was crystallized using 0.1 M HEPES buffer and PEG10000 at pH 7.5. The crystals belonged to tetragonal space group P41212 with cell dimensions of a = b = 72.82 Å and c = 200.37 Å. The structure was determined using the molecular replacement method and refined to values of 0.208 and 0.255 for Rcryst and Rfree factors, respectively. The structure determination showed the presence of three crystallographically independent molecules A, B and C in the asymmetric unit. The molecules A and B are observed in the form of a dimer in the asymmetric unit while molecule C belongs to the second dimer whose partner is related by crystallographic twofold symmetry. The polypeptide chain of KpPPAT folds into a β/α structure. The conformations of the side chains of several residues in the substrate binding site in KpPPAT are significantly different from those reported in other PPATs. As a result, the modes of binding of substrates, phosphopantetheine (PNS) and adenosine triphosphate (ATP) differ considerably. The binding studies using fluorescence spectroscopy indicated a KD value of 3.45 × 10-4 M for ATP which is significantly lower than the corresponding values reported for PPAT from other species.
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Affiliation(s)
- Nabeel Ahmad
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Pradeep Sharma
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Sujata Sharma
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India.
| | - Tej P Singh
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India.
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2
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Sapkota K, Lucas JK, Faulkner JW, Lichte MF, Guo YL, Burke DH, Huang F. Post-transcriptional capping generates coenzyme A-linked RNA. RNA Biol 2024; 21:1-12. [PMID: 38032240 PMCID: PMC10761072 DOI: 10.1080/15476286.2023.2288740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2023] [Indexed: 12/01/2023] Open
Abstract
NAD can be inserted co-transcriptionally via non-canonical initiation to form NAD-RNA. However, that mechanism is unlikely for CoA-linked RNAs due to low intracellular concentration of the required initiator nucleotide, 3'-dephospho-CoA (dpCoA). We report here that phosphopantetheine adenylyltransferase (PPAT), an enzyme of CoA biosynthetic pathway, accepts RNA transcripts as its acceptor substrate and transfers 4'-phosphopantetheine to yield CoA-RNA post-transcriptionally. Synthetic natural (RNAI) and small artificial RNAs were used to identify the features of RNA that are needed for it to serve as PPAT substrate. RNAs with 4-10 unpaired nucleotides at the 5' terminus served as PPAT substrates, but RNAs having <4 unpaired nucleotides did not undergo capping. No capping was observed when the +1A was changed to G or when 5' triphosphate was removed by RNA pyrophosphohydrolase (RppH), suggesting the enzyme recognizes pppA-RNA as an ATP analog. PPAT binding affinities were equivalent for transcripts with +1A, +1 G, or 5'OH (+1A), indicating that productive enzymatic recognition is driven more by local positioning effects than by overall binding affinity. Capping rates were independent of the number of unpaired nucleotides in the range of 4-10 nucleotides. Capping was strongly inhibited by ATP, reducing CoA-RNA production ~70% when equimolar ATP and substrate RNA were present. Dual bacterial expression of candidate RNAs with different 5' structures followed by CoA-RNA CaptureSeq revealed 12-fold enrichment of the better PPAT substrate, consistent with in vivo CoA-capping of RNA transcripts by PPAT. These results suggest post-transcriptional RNA capping as a possible mechanism for the biogenesis of CoA-RNAs in bacteria.
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Affiliation(s)
- Krishna Sapkota
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Jordyn K. Lucas
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Jarrett W. Faulkner
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Matt F. Lichte
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Yan-Lin Guo
- Department of Cell and Molecular Biology, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Donald H. Burke
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO, USA
| | - Faqing Huang
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS, USA
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3
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Thiophosphate Analogs of Coenzyme A and Its Precursors—Synthesis, Stability, and Biomimetic Potential. Biomolecules 2022; 12:biom12081065. [PMID: 36008959 PMCID: PMC9405834 DOI: 10.3390/biom12081065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 02/05/2023] Open
Abstract
Coenzyme A (CoA) is ubiquitous and essential for key cellular processes in any living organism. Primary degradation of CoA occurs by enzyme-mediated pyrophosphate hydrolysis intracellularly and extracellularly to form adenosine 3’,5’-diphosphate and 4’-phosphopantetheine (PPanSH). The latter can be recycled for intracellular synthesis of CoA. Impairments in the CoA biosynthetic pathway are linked to a severe form of neurodegeneration with brain iron accumulation for which no disease-modifying therapy is available. Currently, exogenous administration of PPanSH is examined as a therapeutic intervention. Here, we describe biosynthetic access to thiophosphate analogs of PPanSH, 3′-dephospho-CoA, and CoA. The stabilizing effect of thiophosphate modifications toward degradation by extracellular and peroxisomal enzymes was studied in vitro. Experiments in a CoA-deficient cell model suggest a biomimetic potential of the PPanSH thiophosphate analog PSPanSH (C1). According to our findings, the administration of PSPanSH may provide an alternative approach to support intracellular CoA-dependent pathways.
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4
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Thomas SE, McCarthy WJ, El Bakali J, Brown KP, Kim SY, Blaszczyk M, Mendes V, Abell C, Floto RA, Coyne AG, Blundell TL. Structural Characterization of Mycobacterium abscessus Phosphopantetheine Adenylyl Transferase Ligand Interactions: Implications for Fragment-Based Drug Design. Front Mol Biosci 2022; 9:880432. [PMID: 35712348 PMCID: PMC9197168 DOI: 10.3389/fmolb.2022.880432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 05/09/2022] [Indexed: 02/02/2023] Open
Abstract
Anti-microbial resistance is a rising global healthcare concern that needs urgent attention as growing number of infections become difficult to treat with the currently available antibiotics. This is particularly true for mycobacterial infections like tuberculosis and leprosy and those with emerging opportunistic pathogens such as Mycobacterium abscessus, where multi-drug resistance leads to increased healthcare cost and mortality. M. abscessus is a highly drug-resistant non-tuberculous mycobacterium which causes life-threatening infections in people with chronic lung conditions such as cystic fibrosis. In this study, we explore M. abscessus phosphopantetheine adenylyl transferase (PPAT), an enzyme involved in the biosynthesis of Coenzyme A, as a target for the development of new antibiotics. We provide structural insights into substrate and feedback inhibitor binding modes of M. abscessus PPAT, thereby setting the basis for further chemical exploration of the enzyme. We then utilize a multi-dimensional fragment screening approach involving biophysical and structural analysis, followed by evaluation of compounds from a previous fragment-based drug discovery campaign against M. tuberculosis PPAT ortholog. This allowed the identification of an early-stage lead molecule exhibiting low micro molar affinity against M. abscessus PPAT (Kd 3.2 ± 0.8 µM) and potential new ways to design inhibitors against this enzyme. The resulting crystal structures reveal striking conformational changes and closure of solvent channel of M. abscessus PPAT hexamer providing novel strategies of inhibition. The study thus validates the ligandability of M. abscessus PPAT as an antibiotic target and identifies crucial starting points for structure-guided drug discovery against this bacterium.
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Affiliation(s)
- Sherine E. Thomas
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom,*Correspondence: Sherine E. Thomas, ; Tom L. Blundell,
| | - William J. McCarthy
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Jamal El Bakali
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Karen P. Brown
- MRC Laboratory of Molecular Biology, Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - So Yeon Kim
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Michal Blaszczyk
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Vítor Mendes
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom,MRC Laboratory of Molecular Biology, Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Chris Abell
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - R. Andres Floto
- MRC Laboratory of Molecular Biology, Molecular Immunity Unit, Department of Medicine, University of Cambridge, Cambridge, United Kingdom,Cambridge Centre for Lung Infection, Royal Papworth Hospital, Cambridge, United Kingdom
| | - Anthony G. Coyne
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Tom L. Blundell
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom,*Correspondence: Sherine E. Thomas, ; Tom L. Blundell,
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5
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Ras TA, Strauss E, Botes A. Evaluating the Genetic Capacity of Mycoplasmas for Coenzyme A Biosynthesis in a Search for New Anti-mycoplasma Targets. Front Microbiol 2021; 12:791756. [PMID: 34987490 PMCID: PMC8721197 DOI: 10.3389/fmicb.2021.791756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/22/2021] [Indexed: 12/15/2022] Open
Abstract
Mycoplasmas are responsible for a wide range of disease states in both humans and animals, in which their parasitic lifestyle has allowed them to reduce their genome sizes and curtail their biosynthetic capabilities. The subsequent dependence on their host offers a unique opportunity to explore pathways for obtaining and producing cofactors - such as coenzyme A (CoA) - as possible targets for the development of new anti-mycoplasma agents. CoA plays an essential role in energy and fatty acid metabolism and is required for membrane synthesis. However, our current lack of knowledge of the relevance and importance of the CoA biosynthesis pathway in mycoplasmas, and whether it could be bypassed within their pathogenic context, prevents further exploration of the potential of this pathway. In the universal, canonical CoA biosynthesis pathway, five enzymes are responsible for the production of CoA. Given the inconsistent presence of the genes that code for these enzymes across Mycoplasma genomes, this study set out to establish the genetic capacity of mycoplasmas to synthesize their own CoA de novo. Existing functional annotations and sequence, family, motif, and domain analysis of protein products were used to determine the existence of relevant genes in Mycoplasma genomes. We found that most Mycoplasma species do have the genetic capacity to synthesize CoA, but there was a differentiated prevalence of these genes across species. Phylogenetic analysis indicated that the phylogenetic position of a species could not be used to predict its enzyme-encoding gene combinations. Despite this, the final enzyme in the biosynthesis pathway - dephospho-coenzyme A kinase (DPCK) - was found to be the most common among the studied species, suggesting that it has the most potential as a target in the search for new broad-spectrum anti-mycoplasma agents.
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Affiliation(s)
| | | | - Annelise Botes
- Department of Biochemistry, Stellenbosch University, Stellenbosch, South Africa
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6
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Stautz J, Hellmich Y, Fuss MF, Silberberg JM, Devlin JR, Stockbridge RB, Hänelt I. Molecular Mechanisms for Bacterial Potassium Homeostasis. J Mol Biol 2021; 433:166968. [PMID: 33798529 DOI: 10.1016/j.jmb.2021.166968] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/11/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
Potassium ion homeostasis is essential for bacterial survival, playing roles in osmoregulation, pH homeostasis, regulation of protein synthesis, enzyme activation, membrane potential adjustment and electrical signaling. To accomplish such diverse physiological tasks, it is not surprising that a single bacterium typically encodes several potassium uptake and release systems. To understand the role each individual protein fulfills and how these proteins work in concert, it is important to identify the molecular details of their function. One needs to understand whether the systems transport ions actively or passively, and what mechanisms or ligands lead to the activation or inactivation of individual systems. Combining mechanistic information with knowledge about the physiology under different stress situations, such as osmostress, pH stress or nutrient limitation, one can identify the task of each system and deduce how they are coordinated with each other. By reviewing the general principles of bacterial membrane physiology and describing the molecular architecture and function of several bacterial K+-transporting systems, we aim to provide a framework for microbiologists studying bacterial potassium homeostasis and the many K+-translocating systems that are still poorly understood.
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Affiliation(s)
- Janina Stautz
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Yvonne Hellmich
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Michael F Fuss
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jakob M Silberberg
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jason R Devlin
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Randy B Stockbridge
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States.
| | - Inga Hänelt
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.
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7
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Peraman R, Sure SK, Dusthackeer VNA, Chilamakuru NB, Yiragamreddy PR, Pokuri C, Kutagulla VK, Chinni S. Insights on recent approaches in drug discovery strategies and untapped drug targets against drug resistance. FUTURE JOURNAL OF PHARMACEUTICAL SCIENCES 2021; 7:56. [PMID: 33686369 PMCID: PMC7928709 DOI: 10.1186/s43094-021-00196-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/03/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Despite the various strategies undertaken in the clinical practice, the mortality rate due to antibiotic-resistant microbes has been markedly increasing worldwide. In addition to multidrug-resistant (MDR) microbes, the "ESKAPE" bacteria are also emerging. Of course, the infection caused by ESKAPE cannot be treated even with lethal doses of antibiotics. Now, the drug resistance is also more prevalent in antiviral, anticancer, antimalarial and antifungal chemotherapies. MAIN BODY To date, in the literature, the quantum of research reported on the discovery strategies for new antibiotics is remarkable but the milestone is still far away. Considering the need of the updated strategies and drug discovery approaches in the area of drug resistance among researchers, in this communication, we consolidated the insights pertaining to new drug development against drug-resistant microbes. It includes drug discovery void, gene paradox, transposon mutagenesis, vitamin biosynthesis inhibition, use of non-conventional media, host model, target through quorum sensing, genomic-chemical network, synthetic viability to targets, chemical versus biological space, combinational approach, photosensitization, antimicrobial peptides and transcriptome profiling. Furthermore, we optimally briefed about antievolution drugs, nanotheranostics and antimicrobial adjuvants and then followed by twelve selected new feasible drug targets for new drug design against drug resistance. Finally, we have also tabulated the chemical structures of potent molecules against antimicrobial resistance. CONCLUSION It is highly recommended to execute the anti-drug resistance research as integrated approach where both molecular and genetic research needs to be as integrative objective of drug discovery. This is time to accelerate new drug discovery research with advanced genetic approaches instead of conventional blind screening.
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Affiliation(s)
- Ramalingam Peraman
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous, Anantapur, Andhra Pradesh India
| | - Sathish Kumar Sure
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous, Anantapur, Andhra Pradesh India
| | - V. N. Azger Dusthackeer
- grid.417330.20000 0004 1767 6138ICMR-National Institute of Research in Tuberculosis, Chennai, Tamilnadu India
| | - Naresh Babu Chilamakuru
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous, Anantapur, Andhra Pradesh India
| | - Padmanabha Reddy Yiragamreddy
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous, Anantapur, Andhra Pradesh India
| | - Chiranjeevi Pokuri
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous, Anantapur, Andhra Pradesh India
| | - Vinay Kumar Kutagulla
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous, Anantapur, Andhra Pradesh India
| | - Santhivardhan Chinni
- RERDS-CPR, Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous, Anantapur, Andhra Pradesh India
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8
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Gupta A, Sharma P, Singh TP, Sharma S. Phosphopantetheine Adenylyltransferase: A promising drug target to combat antibiotic resistance. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1869:140566. [PMID: 33271445 DOI: 10.1016/j.bbapap.2020.140566] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 01/11/2023]
Abstract
Phosphopantetheine Adenylyltransferase (PPAT) is an enzyme that catalyzes the penultimate step in the biosynthesis of Coenzyme A (CoA), which is the active and physiologically functional form of dietary Vitamin B5. CoA serves as a cofactor for numerous metabolic reactions which makes it essential for cellular survival. This enzyme is also subject to feedback inhibition by CoA to maintain its cellular concentration. The steps of the CoA biosynthesis pathway remain conserved from prokaryotes to eukaryotes, with humans and pathogenic micro-organisms showing significant diversity on a sequence, structure and mechanistic level. This suggests that the development of selective inhibitors of microbial CoA biosynthesis should be possible using these enzymes as targets for drug development. Bacterial PPAT shows significant mechanistic difference from its human counterpart CoA synthase, which is a dual protein carrying the activity of both PPAT and next step in the pathway catalyzed by the enzyme Dephospho CoA kinase (DPCK). This review covers the detailed description of the mechanistic, structural and functional aspects of this enzyme. Also, all the attempts to design high efficiency inhibitors of this enzyme using the approach of structure based drug design have been discussed in detail. This comprehensive structural and functional discussion of PPAT will help in further exploiting it as a drug target.
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Affiliation(s)
- Akshita Gupta
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Pradeep Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | - Tej P Singh
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India.
| | - Sujata Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India.
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9
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Tascón I, Sousa JS, Corey RA, Mills DJ, Griwatz D, Aumüller N, Mikusevic V, Stansfeld PJ, Vonck J, Hänelt I. Structural basis of proton-coupled potassium transport in the KUP family. Nat Commun 2020; 11:626. [PMID: 32005818 PMCID: PMC6994465 DOI: 10.1038/s41467-020-14441-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 01/10/2020] [Indexed: 12/05/2022] Open
Abstract
Potassium homeostasis is vital for all organisms, but is challenging in single-celled organisms like bacteria and yeast and immobile organisms like plants that constantly need to adapt to changing external conditions. KUP transporters facilitate potassium uptake by the co-transport of protons. Here, we uncover the molecular basis for transport in this widely distributed family. We identify the potassium importer KimA from Bacillus subtilis as a member of the KUP family, demonstrate that it functions as a K+/H+ symporter and report a 3.7 Å cryo-EM structure of the KimA homodimer in an inward-occluded, trans-inhibited conformation. By introducing point mutations, we identify key residues for potassium and proton binding, which are conserved among other KUP proteins. KUP transporters facilitate potassium uptake by the co-transport of protons and are key players in potassium homeostasis. Here authors identify the potassium importer KimA from Bacillus subtilis as a new member of the KUP transporter family and show the cryo-EM structure of KimA in an inward-occluded, trans-inhibited conformation.
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Affiliation(s)
- Igor Tascón
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Joana S Sousa
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Robin A Corey
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Deryck J Mills
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - David Griwatz
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Nadine Aumüller
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Vedrana Mikusevic
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Phillip J Stansfeld
- Department of Biochemistry, University of Oxford, Oxford, UK.,School of Life Sciences & Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| | - Inga Hänelt
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.
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10
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Zhu W, Radadiya A, Bisson C, Wenzel S, Nordin BE, Martínez-Márquez F, Imasaki T, Sedelnikova SE, Coricello A, Baumann P, Berry AH, Nomanbhoy TK, Kozarich JW, Jin Y, Rice DW, Takagi Y, Richards NGJ. High-resolution crystal structure of human asparagine synthetase enables analysis of inhibitor binding and selectivity. Commun Biol 2019; 2:345. [PMID: 31552298 PMCID: PMC6748925 DOI: 10.1038/s42003-019-0587-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 08/21/2019] [Indexed: 12/20/2022] Open
Abstract
Expression of human asparagine synthetase (ASNS) promotes metastatic progression and tumor cell invasiveness in colorectal and breast cancer, presumably by altering cellular levels of L-asparagine. Human ASNS is therefore emerging as a bona fide drug target for cancer therapy. Here we show that a slow-onset, tight binding inhibitor, which exhibits nanomolar affinity for human ASNS in vitro, exhibits excellent selectivity at 10 μM concentration in HCT-116 cell lysates with almost no off-target binding. The high-resolution (1.85 Å) crystal structure of human ASNS has enabled us to identify a cluster of negatively charged side chains in the synthetase domain that plays a key role in inhibitor binding. Comparing this structure with those of evolutionarily related AMP-forming enzymes provides insights into intermolecular interactions that give rise to the observed binding selectivity. Our findings demonstrate the feasibility of developing second generation human ASNS inhibitors as lead compounds for the discovery of drugs against metastasis. Wen Zhu et al. report the crystal structure of human asparagine synthetase at a 1.85 Å resolution, enabling computational analysis of inhibitor binding. They also find new insights into the intermolecular interactions contributing to binding specificity of inhibitors.
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Affiliation(s)
- Wen Zhu
- 1School of Chemistry, Cardiff University, Cardiff, UK.,8Present Address: Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, CA USA
| | | | - Claudine Bisson
- 2Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK.,8Present Address: Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, CA USA
| | - Sabine Wenzel
- 3Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN USA
| | - Brian E Nordin
- 4ActivX Biosciences, Inc, La Jolla, CA USA.,Present Address: Vividion Therapeutics, San Diego, CA USA
| | - Francisco Martínez-Márquez
- 3Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN USA
| | - Tsuyoshi Imasaki
- 3Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN USA.,5Division of Structural Medicine and Anatomy, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Svetlana E Sedelnikova
- 2Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | | | | | - Alexandria H Berry
- 6Department of Biology, California Institute of Technology, Pasadena, CA USA
| | | | | | - Yi Jin
- 1School of Chemistry, Cardiff University, Cardiff, UK
| | - David W Rice
- 2Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Yuichiro Takagi
- 3Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN USA
| | - Nigel G J Richards
- 1School of Chemistry, Cardiff University, Cardiff, UK.,7Foundation for Applied Molecular Evolution, Alachua, FL USA
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11
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Gupta A, Singh PK, Sharma P, Kaur P, Sharma S, Singh TP. Structural and biochemical studies of phosphopantetheine adenylyltransferase from Acinetobacter baumannii with dephospho-coenzyme A and coenzyme A. Int J Biol Macromol 2019; 142:181-190. [PMID: 31525415 DOI: 10.1016/j.ijbiomac.2019.09.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/11/2019] [Accepted: 09/11/2019] [Indexed: 11/29/2022]
Abstract
Phosphopantetheine adenylyl transferase catalyzes a rate limiting penultimate step of the multistep reaction which produces coenzyme A (CoA) as a final product. CoA is required as an essential cofactor in a number of metabolic reactions. Therefore inhibiting the function of this enzyme will lead to cell death in bacteria. Acinetobacter baumannii is multi drug resistant pathogen and causes infections in immunocompromised patients. AbPPAT has been cloned, expressed, purified and crystallized and structures of two complexes of AbPPAT with dephospho coenzyme A (dPCoA) and coenzyme A (CoA) have been determined. Both dPCoA and CoA molecules are observed in the substrate binding site of AbPPAT. A comparison with the structures of the complexes of PPAT from other species shows that the orientations of dPCoA are identical in all the structures. On the other hand, as observed from the structures of the complexes of CoA with PPAT, the orientations of CoA are found to differ considerably. This shows that the substrates occupy identical positions in the substrate binding sites of enzymes whereas the positions of inhibitors may differ. The binding studies carried out using fluorescence method and surface plasmon resonance techniques showed that binding affinity of CoA towards AbPPAT is nearly three times higher than that of dPCoA.
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Affiliation(s)
- A Gupta
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - P K Singh
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - P Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - P Kaur
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - S Sharma
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - T P Singh
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
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12
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Duncan D, Auclair K. The coenzyme A biosynthetic pathway: A new tool for prodrug bioactivation. Arch Biochem Biophys 2019; 672:108069. [PMID: 31404525 DOI: 10.1016/j.abb.2019.108069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/05/2019] [Accepted: 08/08/2019] [Indexed: 11/29/2022]
Abstract
Prodrugs account for more than 5% of pharmaceuticals approved worldwide. Over the past decades several prodrug design strategies have been firmly established; however, only a few functional groups remain amenable to this approach. The aim of this overview is to highlight the use of coenzyme A (CoA) biosynthetic enzymes as a recently explored bioactivation scheme and provide information about its scope of utility. This emerging tool is likely to have a strong impact on future medicinal and biological studies as it offers promiscuity, orthogonal selectivity, and the capability of assembling exceptionally large molecules.
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Affiliation(s)
- Dustin Duncan
- Department of Chemistry, McGill University, Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada
| | - Karine Auclair
- Department of Chemistry, McGill University, Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada.
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13
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Singh H, Das S, Yadav J, Srivastava VK, Jyoti A, Kaushik S. In search of novel protein drug targets for treatment of Enterococcus faecalis infections. Chem Biol Drug Des 2019; 94:1721-1739. [PMID: 31260188 DOI: 10.1111/cbdd.13582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/08/2019] [Accepted: 06/17/2019] [Indexed: 12/27/2022]
Abstract
Enterococcus faecalis (Ef) is one of the major pathogens involved in hospital-acquired infections. It can cause nosocomial bacteremia, surgical wound infection, and urinary tract infection. It is important to mention here that Ef is developing resistance against many commonly occurring antibiotics. The occurrence of multidrug resistance (MDR) and extensive-drug resistance (XDR) is now posing a major challenge to the medical community. In this regard, to combat the infections caused by Ef, we have to look for an alternative. Rational structure-based drug design exploits the three-dimensional structure of the target protein, which can be unraveled by various techniques such as X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. In this review, we have discussed the complete picture of Ef infections, the possible treatment available at present, and the alternative treatment options to be explored. This study will help in better understanding of novel biological targets against Ef and the compounds, which are likely to bind with these targets. Using these detailed structural informations, rational structure-based drug design is achievable and tight inhibitors against Ef can be prepared.
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Affiliation(s)
- Harpreet Singh
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Satyajeet Das
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Jyoti Yadav
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | | | - Anupam Jyoti
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Sanket Kaushik
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
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14
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Structural and binding studies of phosphopantetheine adenylyl transferase from Acinetobacter baumannii. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1867:537-547. [DOI: 10.1016/j.bbapap.2019.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 02/25/2019] [Accepted: 03/13/2019] [Indexed: 11/21/2022]
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15
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Guan J, Vong K, Wee K, Fakhoury J, Dullaghan E, Auclair K. Cellular Studies of an Aminoglycoside Potentiator Reveal a New Inhibitor of Aminoglycoside Resistance. Chembiochem 2018; 19:2107-2113. [DOI: 10.1002/cbic.201800368] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Jinming Guan
- Department of Chemistry; McGill University; 801 Sherbrooke Street West Montreal Quebec H3A 0B8 Canada
| | - Kenward Vong
- Department of Chemistry; McGill University; 801 Sherbrooke Street West Montreal Quebec H3A 0B8 Canada
| | - Kathleen Wee
- Target Validation Division; The Centre for Drug Research and Development; 2405 Westbrook Mall, 4th Floor Vancouver British Columbia V6T 1Z3 Canada
| | - Johans Fakhoury
- Department of Chemistry; McGill University; 801 Sherbrooke Street West Montreal Quebec H3A 0B8 Canada
| | - Edie Dullaghan
- Target Validation Division; The Centre for Drug Research and Development; 2405 Westbrook Mall, 4th Floor Vancouver British Columbia V6T 1Z3 Canada
| | - Karine Auclair
- Department of Chemistry; McGill University; 801 Sherbrooke Street West Montreal Quebec H3A 0B8 Canada
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16
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Acetate-dependent tRNA acetylation required for decoding fidelity in protein synthesis. Nat Chem Biol 2018; 14:1010-1020. [PMID: 30150682 DOI: 10.1038/s41589-018-0119-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 07/09/2018] [Indexed: 11/08/2022]
Abstract
Modification of tRNA anticodons plays a critical role in ensuring accurate translation. N4-acetylcytidine (ac4C) is present at the anticodon first position (position 34) of bacterial elongator tRNAMet. Herein, we identified Bacillus subtilis ylbM (renamed tmcAL) as a novel gene responsible for ac4C34 formation. Unlike general acetyltransferases that use acetyl-CoA, TmcAL activates an acetate ion to form acetyladenylate and then catalyzes ac4C34 formation through a mechanism similar to tRNA aminoacylation. The crystal structure of TmcAL with an ATP analog reveals the molecular basis of ac4C34 formation. The ΔtmcAL strain displayed a cold-sensitive phenotype and a strong genetic interaction with tilS that encodes the enzyme responsible for synthesizing lysidine (L) at position 34 of tRNAIle to facilitate AUA decoding. Mistranslation of the AUA codon as Met in the ΔtmcAL strain upon tilS repression suggests that ac4C34 modification of tRNAMet and L34 modification of tRNAIle act cooperatively to prevent misdecoding of the AUA codon.
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17
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Skepper CK, Moreau RJ, Appleton BA, Benton BM, Drumm JE, Feng BY, Geng M, Hu C, Li C, Lingel A, Lu Y, Mamo M, Mergo W, Mostafavi M, Rath CM, Steffek M, Takeoka KT, Uehara K, Wang L, Wei JR, Xie L, Xu W, Zhang Q, de Vicente J. Discovery and Optimization of Phosphopantetheine Adenylyltransferase Inhibitors with Gram-Negative Antibacterial Activity. J Med Chem 2018; 61:3325-3349. [DOI: 10.1021/acs.jmedchem.7b01861] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Colin K. Skepper
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Robert J. Moreau
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Brent A. Appleton
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Bret M. Benton
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Joseph E. Drumm
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Brian Y. Feng
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Mei Geng
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Cheng Hu
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Cindy Li
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Andreas Lingel
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Yipin Lu
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Mulugeta Mamo
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Wosenu Mergo
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Mina Mostafavi
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Christopher M. Rath
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Micah Steffek
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Kenneth T. Takeoka
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Kyoko Uehara
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Lisha Wang
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Jun-Rong Wei
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Lili Xie
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Wenjian Xu
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Qiong Zhang
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Javier de Vicente
- Novartis Institutes for Biomedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
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18
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Moreau RJ, Skepper CK, Appleton BA, Blechschmidt A, Balibar CJ, Benton BM, Drumm JE, Feng BY, Geng M, Li C, Lindvall MK, Lingel A, Lu Y, Mamo M, Mergo W, Polyakov V, Smith TM, Takeoka K, Uehara K, Wang L, Wei JR, Weiss AH, Xie L, Xu W, Zhang Q, de Vicente J. Fragment-Based Drug Discovery of Inhibitors of Phosphopantetheine Adenylyltransferase from Gram-Negative Bacteria. J Med Chem 2018; 61:3309-3324. [DOI: 10.1021/acs.jmedchem.7b01691] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Robert J. Moreau
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Colin K. Skepper
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Brent A. Appleton
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Anke Blechschmidt
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Carl J. Balibar
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Bret M. Benton
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Joseph E. Drumm
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Brian Y. Feng
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Mei Geng
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Cindy Li
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Mika K. Lindvall
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Andreas Lingel
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Yipin Lu
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Mulugeta Mamo
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Wosenu Mergo
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Valery Polyakov
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Thomas M. Smith
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Kenneth Takeoka
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Kyoko Uehara
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Lisha Wang
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Jun-Rong Wei
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Andrew H. Weiss
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Lili Xie
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Wenjian Xu
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Qiong Zhang
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Javier de Vicente
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
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19
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Mondal A, Chatterjee R, Datta S. Umbrella Sampling and X-ray Crystallographic Analysis Unveil an Arg-Asp Gate Facilitating Inhibitor Binding Inside Phosphopantetheine Adenylyltransferase Allosteric Cleft. J Phys Chem B 2018; 122:1551-1559. [PMID: 29345931 DOI: 10.1021/acs.jpcb.7b09543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Phosphopantetheine adenylyltransferase (PPAT) is a rate-limiting enzyme essential for biosynthesis of coenzyme A (CoA), which in turn is responsible to regulate the secretion of exotoxins via type III secretion system in Pseudomonas aeruginosa, causing severe health concerns ranging from nosocomial infections to respiratory failure. Acetyl coenzyme A (AcCoA) is a newly reported inhibitor of PPAT, believed to regulate the cellular levels of CoA and thereby the pathogenesis. Very little is known so far regarding the mechanistic details of AcCoA binding inside PPAT-binding cleft. Herein, we have used extensive umbrella sampling simulations to decipher mechanistic insight into the inhibitor accommodation inside the binding cavity. We found that R90 and D94 residues act like a gate near the binding cavity to accommodate and stabilize the incoming ligand. Mutational models concerning these residues also show considerable difference in AcCoA-binding thermodynamics. To substantiate our findings, we have solved the first crystal structure of apo-PPAT from P. aeruginosa, which also found to agree with the simulation results. Collectively, these results describe the mechanistic details of accommodation of inhibitor molecule inside PPAT-binding cavity and also offer valuable insight into regulating cellular levels of CoA/AcCoA and thus controlling the pathogenicity.
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Affiliation(s)
- A Mondal
- Structural Biology and Bioinformatics Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology , 4 Raja SC Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - R Chatterjee
- Structural Biology and Bioinformatics Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology , 4 Raja SC Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - S Datta
- Structural Biology and Bioinformatics Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology , 4 Raja SC Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
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20
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Plesa C, Sidore AM, Lubock NB, Zhang D, Kosuri S. Multiplexed gene synthesis in emulsions for exploring protein functional landscapes. Science 2018; 359:343-347. [PMID: 29301959 PMCID: PMC6261299 DOI: 10.1126/science.aao5167] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/18/2017] [Indexed: 12/14/2022]
Abstract
Improving our ability to construct and functionally characterize DNA sequences would broadly accelerate progress in biology. Here, we introduce DropSynth, a scalable, low-cost method to build thousands of defined gene-length constructs in a pooled (multiplexed) manner. DropSynth uses a library of barcoded beads that pull down the oligonucleotides necessary for a gene's assembly, which are then processed and assembled in water-in-oil emulsions. We used DropSynth to successfully build more than 7000 synthetic genes that encode phylogenetically diverse homologs of two essential genes in Escherichia coli We tested the ability of phosphopantetheine adenylyltransferase homologs to complement a knockout E. coli strain in multiplex, revealing core functional motifs and reasons underlying homolog incompatibility. DropSynth coupled with multiplexed functional assays allows us to rationally explore sequence-function relationships at an unprecedented scale.
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Affiliation(s)
- Calin Plesa
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
| | - Angus M. Sidore
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California, USA
| | - Nathan B. Lubock
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
| | - Di Zhang
- Genomics and Computational Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sriram Kosuri
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
- UCLA-DOE Institute for Genomics and Proteomics, Molecular Biology Institute, Quantitative and Computational Biology Institute, Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, California, USA
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21
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Park J, Kim H, Kim S, Lee D, Kim MS, Shin DH. Crystal structure of D-glycero-Β-D-manno-heptose-1-phosphate adenylyltransferase fromBurkholderia pseudomallei. Proteins 2017; 86:124-131. [DOI: 10.1002/prot.25398] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/02/2017] [Accepted: 10/04/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Jimin Park
- College of Pharmacy; Ewha W. University; Seoul Republic of Korea
| | - Hyojin Kim
- College of Pharmacy; Ewha W. University; Seoul Republic of Korea
| | - Suwon Kim
- College of Pharmacy; Ewha W. University; Seoul Republic of Korea
| | - Daeun Lee
- College of Pharmacy; Ewha W. University; Seoul Republic of Korea
| | - Mi-Sun Kim
- College of Pharmacy; Ewha W. University; Seoul Republic of Korea
| | - Dong Hae Shin
- College of Pharmacy; Ewha W. University; Seoul Republic of Korea
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22
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Thomas SE, Mendes V, Kim SY, Malhotra S, Ochoa-Montaño B, Blaszczyk M, Blundell TL. Structural Biology and the Design of New Therapeutics: From HIV and Cancer to Mycobacterial Infections: A Paper Dedicated to John Kendrew. J Mol Biol 2017; 429:2677-2693. [PMID: 28648615 DOI: 10.1016/j.jmb.2017.06.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/19/2017] [Indexed: 10/19/2022]
Abstract
Interest in applications of protein crystallography to medicine was evident, as the first high-resolution structures emerged in the 50s and 60s. In Cambridge, Max Perutz and John Kendrew sought to understand mutations in sickle cell and other genetic diseases related to hemoglobin, while in Oxford, the group of Dorothy Hodgkin became interested in long-lasting zinc-insulin crystals for treatment of diabetes and later considered insulin redesign, as synthetic insulins became possible. The use of protein crystallography in structure-guided drug discovery emerged as enzyme structures allowed the identification of potential inhibitor-binding sites and optimization of interactions of hits using the structure of the target protein. Early examples of this approach were the use of the structure of renin to design antihypertensives and the structure of HIV protease in design of AIDS antivirals. More recently, use of structure-guided design with fragment-based drug discovery, which reduces the size of screening libraries by decreasing complexity, has improved ligand efficiency in drug design and has been used to progress three oncology drugs through clinical trials to FDA approval. We exemplify current developments in structure-guided target identification and fragment-based lead discovery with efforts to develop new antimicrobials for mycobacterial infections.
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Affiliation(s)
- Sherine E Thomas
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA UK
| | - Vitor Mendes
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA UK
| | - So Yeon Kim
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA UK
| | - Sony Malhotra
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA UK
| | - Bernardo Ochoa-Montaño
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA UK
| | - Michal Blaszczyk
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA UK
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA UK.
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23
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Chatterjee R, Mondal A, Basu A, Datta S. Transition of phosphopantetheine adenylyltransferase from catalytic to allosteric state is characterized by ternary complex formation in Pseudomonas aeruginosa. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:773-86. [DOI: 10.1016/j.bbapap.2016.03.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/02/2016] [Accepted: 03/28/2016] [Indexed: 01/28/2023]
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24
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Proudfoot A, Frank AO, Ruggiu F, Mamo M, Lingel A. Facilitating unambiguous NMR assignments and enabling higher probe density through selective labeling of all methyl containing amino acids. JOURNAL OF BIOMOLECULAR NMR 2016; 65:15-27. [PMID: 27130242 DOI: 10.1007/s10858-016-0032-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 04/19/2016] [Indexed: 05/05/2023]
Abstract
The deuteration of proteins and selective labeling of side chain methyl groups has greatly enhanced the molecular weight range of proteins and protein complexes which can be studied using solution NMR spectroscopy. Protocols for the selective labeling of all six methyl group containing amino acids individually are available, however to date, only a maximum of five amino acids have been labeled simultaneously. Here, we describe a new methodology for the simultaneous, selective labeling of all six methyl containing amino acids using the 115 kDa homohexameric enzyme CoaD from E. coli as a model system. The utility of the labeling protocol is demonstrated by efficiently and unambiguously assigning all methyl groups in the enzymatic active site using a single 4D (13)C-resolved HMQC-NOESY-HMQC experiment, in conjunction with a crystal structure. Furthermore, the six fold labeled protein was employed to characterize the interaction between the substrate analogue (R)-pantetheine and CoaD by chemical shift perturbations, demonstrating the benefit of the increased probe density.
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Affiliation(s)
- Andrew Proudfoot
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, CA, 94608, USA
| | - Andreas O Frank
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, CA, 94608, USA
| | - Fiorella Ruggiu
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, CA, 94608, USA
| | - Mulugeta Mamo
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, CA, 94608, USA
| | - Andreas Lingel
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, CA, 94608, USA.
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25
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Abstract
Pantothenate is vitamin B5 and is the key precursor for the biosynthesis of coenzyme A (CoA), a universal and essential cofactor involved in a myriad of metabolic reactions, including the synthesis of phospholipids, the synthesis and degradation of fatty acids, and the operation of the tricarboxylic acid cycle. CoA is also the only source of the phosphopantetheine prosthetic group for enzymes that shuttle intermediates between the active sites of enzymes involved in fatty acid, nonribosomal peptide, and polyketide synthesis. Pantothenate can be synthesized de novo and/or transported into the cell through a pantothenatepermease. Pantothenate uptake is essential for those organisms that lack the genes to synthesize this vitamin. The intracellular levels of CoA are controlled by the balance between synthesis and degradation. In particular, CoA is assembled in five enzymatic steps, starting from the phosphorylation of pantothenate to phosphopantothenatecatalyzed by pantothenate kinase, the product of the coaA gene. In some bacteria, the production of phosphopantothenate by pantothenate kinase is the rate limiting and most regulated step in the biosynthetic pathway. CoA synthesis additionally networks with other vitamin-associated pathways, such as thiamine and folic acid.
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26
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Timofeev VI, Chupova LA, Esipov RS, Kuranova IP. Crystallization and preliminary X-ray diffraction study of phosphopantetheine adenylyltransferase from M. tuberculosis crystallizing in space group P32. CRYSTALLOGR REP+ 2015. [DOI: 10.1134/s106377451505017x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Serrano A, Sebastián M, Arilla-Luna S, Baquedano S, Pallarés MC, Lostao A, Herguedas B, Velázquez-Campoy A, Martínez-Júlvez M, Medina M. Quaternary organization in a bifunctional prokaryotic FAD synthetase: Involvement of an arginine at its adenylyltransferase module on the riboflavin kinase activity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:897-906. [DOI: 10.1016/j.bbapap.2015.03.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 03/11/2015] [Accepted: 03/15/2015] [Indexed: 01/14/2023]
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Alteration of the coenzyme A biosynthetic pathway in neurodegeneration with brain iron accumulation syndromes. Biochem Soc Trans 2015; 42:1069-74. [PMID: 25110004 DOI: 10.1042/bst20140106] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
NBIA (neurodegeneration with brain iron accumulation) comprises a heterogeneous group of neurodegenerative diseases having as a common denominator, iron overload in specific brain areas, mainly basal ganglia and globus pallidus. In the past decade a bunch of disease genes have been identified, but NBIA pathomechanisms are still not completely clear. PKAN (pantothenate kinase-associated neurodegeneration), an autosomal recessive disorder with progressive impairment of movement, vision and cognition, is the most common form of NBIA. It is caused by mutations in the PANK2 (pantothenate kinase 2) gene, coding for a mitochondrial enzyme that phosphorylates vitamin B5 in the first reaction of the CoA (coenzyme A) biosynthetic pathway. A distinct form of NBIA, denominated CoPAN (CoA synthase protein-associated neurodegeneration), is caused by mutations in the CoASY (CoA synthase) gene coding for a bifunctional mitochondrial enzyme, which catalyses the final steps of CoA biosynthesis. These two inborn errors of CoA metabolism further support the concept that dysfunctions in CoA synthesis may play a crucial role in the pathogenesis of NBIA.
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Salzano AM, Novi G, Arioli S, Corona S, Mora D, Scaloni A. Mono-dimensional blue native-PAGE and bi-dimensional blue native/urea-PAGE or/SDS-PAGE combined with nLC–ESI-LIT-MS/MS unveil membrane protein heteromeric and homomeric complexes in Streptococcus thermophilus. J Proteomics 2013; 94:240-61. [DOI: 10.1016/j.jprot.2013.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/04/2013] [Accepted: 09/14/2013] [Indexed: 02/06/2023]
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Discovery of inhibitors of 4'-phosphopantetheine adenylyltransferase (PPAT) to validate PPAT as a target for antibacterial therapy. Antimicrob Agents Chemother 2013; 57:6005-15. [PMID: 24041904 DOI: 10.1128/aac.01661-13] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Inhibitors of 4'-phosphopantetheine adenylyltransferase (PPAT) were identified through high-throughput screening of the AstraZeneca compound library. One series, cycloalkyl pyrimidines, showed inhibition of PPAT isozymes from several species, with the most potent inhibition of enzymes from Gram-positive species. Mode-of-inhibition studies with Streptococcus pneumoniae and Staphylococcus aureus PPAT demonstrated representatives of this series to be reversible inhibitors competitive with phosphopantetheine and uncompetitive with ATP, binding to the enzyme-ATP complex. The potency of this series was optimized using structure-based design, and inhibition of cell growth of Gram-positive species was achieved. Mode-of-action studies, using generation of resistant mutants with targeted sequencing as well as constructs that overexpress PPAT, demonstrated that growth suppression was due to inhibition of PPAT. An effect on bacterial burden was demonstrated in mouse lung and thigh infection models, but further optimization of dosing requirements and compound properties is needed before these compounds can be considered for progress into clinical development. These studies validated PPAT as a novel target for antibacterial therapy.
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Cheng CS, Jia KF, Chen T, Chang SY, Lin MS, Yin HS. Experimentally validated novel inhibitors of Helicobacter pylori phosphopantetheine adenylyltransferase discovered by virtual high-throughput screening. PLoS One 2013; 8:e74271. [PMID: 24040220 PMCID: PMC3764209 DOI: 10.1371/journal.pone.0074271] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 07/30/2013] [Indexed: 11/23/2022] Open
Abstract
Helicobacter pylori is a major etiologic agent associated with the development and maintenance of human gastritis. The goal of this study was to develop novel antibiotics against H. pylori, and we thus targeted H. pylori phosphopantetheine adenylyltransferase (HpPPAT). PPAT catalyzes the penultimate step in coenzyme A biosynthesis. Its inactivation effectively prevents bacterial viability, making it an attractive target for antibacterial drug discovery. We employed virtual high-throughput screening and the HpPPAT crystal structure to identify compounds in the PubChem database that might act as inhibitors of HpPPAT. d-amethopterin is a potential inhibitor for blocking HpPPAT activity and suppressing H. pylori viability. Following treatment with d-amethopterin, H. pylori exhibited morphological characteristics associated with cell death. d-amethopterin is a mixed inhibitor of HpPPAT activity; it simultaneously occupies the HpPPAT 4'-phosphopantetheine- and ATP-binding sites. Its binding affinity is in the micromolar range, implying that it is sufficiently potent to serve as a lead compound in subsequent drug development. Characterization of the d-amethopterin and HpPPAT interaction network in a docked model will allow us to initiate rational drug optimization to improve the inhibitory efficacy of d-amethopterin. We anticipate that novel, potent, and selective HpPPAT inhibitors will emerge for the treatment of H. pylori infection.
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Affiliation(s)
- Chao-Sheng Cheng
- Institute of Bioinformatics and Structural Biology and College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Kai-Fan Jia
- Institute of Bioinformatics and Structural Biology and College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Ting Chen
- Institute of Bioinformatics and Structural Biology and College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Shun-Ya Chang
- Institute of Bioinformatics and Structural Biology and College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | | | - Hsien-Sheng Yin
- Institute of Bioinformatics and Structural Biology and College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
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Li L, Martinis SA, Luthey-Schulten Z. Capture and quality control mechanisms for adenosine-5'-triphosphate binding. J Am Chem Soc 2013; 135:6047-55. [PMID: 23276298 DOI: 10.1021/ja308044w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The catalytic events in members of the nucleotidylyl transferase superfamily are initiated by a millisecond binding of ATP in the active site. Through metadynamics simulations on a class I aminoacyl-tRNA synthetase (aaRSs), the largest group in the superfamily, we calculate the free energy landscape of ATP selection and binding. Mutagenesis studies and fluorescence spectroscopy validated the identification of the most populated intermediate states. The rapid first binding step involves formation of encounter complexes captured through a fly casting mechanism that acts upon the triphosphate moiety of ATP. In the slower nucleoside binding step, a conserved histidine in the HxxH motif orients the incoming ATP through base-stacking interactions resulting in a deep minimum in the free energy surface. Mutation of this histidine significantly decreases the binding affinity measured experimentally and computationally. The metadynamics simulations further reveal an intermediate quality control state that the synthetases and most likely other members of the superfamily use to select ATP over other nucleoside triphosphates.
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Affiliation(s)
- Li Li
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Timofeev V, Smirnova E, Chupova L, Esipov R, Kuranova I. X-ray study of the conformational changes in the molecule of phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis during the catalyzed reaction. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:1660-70. [PMID: 23151631 DOI: 10.1107/s0907444912040206] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 09/22/2012] [Indexed: 11/11/2022]
Abstract
Structures of recombinant phosphopantetheine adenylyltransferase (PPAT) from Mycobacterium tuberculosis (PPATMt) in the apo form and in complex with the substrate ATP were determined at 1.62 and 1.70 Å resolution, respectively, using crystals grown in microgravity by the counter-diffusion method. The ATP molecule of the PPATMt-ATP complex was located with full occupancy in the active-site cavity. Comparison of the solved structures with previously determined structures of PPATMt complexed with the reaction product dephosphocoenzyme A (dPCoA) and the feedback inhibitor coenzyme A (CoA) was performed using superposition on C(α) atoms. The peculiarities of the arrangement of the ligands in the active-site cavity of PPATMt are described. The conformational states of the PPAT molecule in the consequent steps of the catalyzed reaction in the apo enzyme and the enzyme-substrate and enzyme-product complexes are characterized. It is shown that the binding of ATP and dPCoA induces the rearrangement of a short part of the polypeptide chain restricting the active-site cavity in the subunits of the hexameric enzyme molecule. The changes in the quaternary structure caused by this rearrangement are accompanied by a variation of the size of the inner water-filled channel which crosses the PPAT molecule along the threefold axis of the hexamer. The molecular mechanism of the observed changes is described.
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Affiliation(s)
- Vladimir Timofeev
- Laboratory of X-ray Analysis Methods and Synchrotron Radiation, Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky Prospect 59, Moscow, Russian Federation.
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Role of key residues at the flavin mononucleotide (FMN):adenylyltransferase catalytic site of the bifunctional riboflavin kinase/flavin adenine dinucleotide (FAD) Synthetase from Corynebacterium ammoniagenes. Int J Mol Sci 2012. [PMID: 23203077 PMCID: PMC3509593 DOI: 10.3390/ijms131114492] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
In mammals and in yeast the conversion of Riboflavin (RF) into flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) is catalysed by the sequential action of two enzymes: an ATP:riboflavin kinase (RFK) and an ATP:FMN adenylyltransferase (FMNAT). However, most prokaryotes depend on a single bifunctional enzyme, FAD synthetase (FADS), which folds into two modules: the C-terminal associated with RFK activity and the N-terminal associated with FMNAT activity. Sequence and structural analysis suggest that the 28-HxGH-31, 123-Gx(D/N)-125 and 161-xxSSTxxR-168 motifs from FADS must be involved in ATP stabilisation for the adenylylation of FMN, as well as in FAD stabilisation for FAD phyrophosphorolysis. Mutants were produced at these motifs in the Corynebacterium ammoniagenes FADS (CaFADS). Their effects on the kinetic parameters of CaFADS activities (RFK, FMNAT and FAD pyrophosphorilase), and on substrates and product binding properties indicate that H28, H31, N125 and S164 contribute to the geometry of the catalytically competent complexes at the FMNAT-module of CaFADS.
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Cheng CS, Chen WT, Chen YW, Chen CH, Luo YC, Lyu PC, Yin HS. Substitution of asparagine 76 by a tyrosine residue induces domain swapping in Helicobacter pylori phosphopantetheine adenylyltransferase. J Biomol Struct Dyn 2012; 30:488-502. [PMID: 22694317 DOI: 10.1080/07391102.2012.682213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Phosphopantetheine adenylyltransferase (PPAT) catalyses the penultimate step in coenzyme A biosynthesis in bacteria and is therefore a candidate target for antibacterial drug development. We randomly mutated the residues in the Helicobacter pylori PPAT sequence to identify those that govern protein folding and ligand binding, and we describe the crystal structure of one of these mutants (I4V/N76Y) that contains the mutations I4 → V and N76 → Y. Unlike other PPATs, which are homohexamers, I4V/N76Y is a domain-swapped homotetramer. The protomer structure of this mutant is an open conformation in which the 65 C-terminal residues are intertwined with those of a neighbouring protomer. Despite structural differences between wild-type PPAT and IV4/N76Y, they had similar ligand-binding properties. ATP binding to these two proteins was enthalpically driven, whereas that for Escherichia coli PPAT is entropically driven. The structural packing of the subunits may affect the thermal denaturation of wild-type PPAT and I4V/N76Y. Mutations in hinge regions often induce domain swapping, i.e. the spatial exchange of portions of adjacent protomers, but residues 4 and 76 of H. pylori PPAT are not located in or near to the hinge region. However, one or both of these residues is responsible for the large conformational change in the C-terminal region of each protomer. To identify the residue(s) responsible, we constructed the single-site mutant, N76Y, and found a large displacement of α-helix 4, which indicated that its flexibility allowed the domain swap to occur.
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Affiliation(s)
- Chao-Sheng Cheng
- Institute of Bioinformatics and Structural Biology, and College of Life Sciences, National Tsing Hua University, Hsinchu, 300, Taiwan
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36
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Timofeev VI, Smirnova EA, Chupova LA, Esipov RS, Kuranova IP. Three-dimensional structure of phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis in the apo form and in complexes with coenzyme A and dephosphocoenzyme A. CRYSTALLOGR REP+ 2012. [DOI: 10.1134/s1063774512010142] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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37
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Yoon HJ, Kang JY, Mikami B, Lee HH, Suh SW. Crystal structure of phosphopantetheine adenylyltransferase from Enterococcus faecalis in the ligand-unbound state and in complex with ATP and pantetheine. Mol Cells 2011; 32:431-5. [PMID: 21912874 PMCID: PMC3887696 DOI: 10.1007/s10059-011-0102-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/21/2011] [Accepted: 08/23/2011] [Indexed: 11/29/2022] Open
Abstract
Phosphopantetheine adenylyltransferase (PPAT) catalyzes the reversible transfer of an adenylyl group from ATP to 4'-phosphopantetheine (Ppant) to form dephospho-CoA (dPCoA) and pyrophosphate in the Coenzyme A (CoA) biosynthetic pathway. Importantly, PPATs are the potential target for developing antibiotics because bacterial and mammalian PPATs share little sequence homology. Previous structural studies revealed the mechanism of the recognizing substrates and products. The binding modes of ATP, ADP, Ppant, and dPCoA are highly similar in all known structures, whereas the binding modes of CoA or 3'-phosphoadenosine 5'-phosphosulfate binding are novel. To provide further structural information on ligand binding by PPATs, the crystal structure of PPAT from Enterococcus faecalis was solved in three forms: (i) apo form, (ii) binary complex with ATP, and (iii) binary complex with pantetheine. The substrate analog, pantetheine, binds to the active site in a similar manner to Ppant. The new structural information reported in this study including pantetheine as a potent inhibitor of PPAT will supplement the existing structural data and should be useful for structure-based antibacterial discovery against PPATs.
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Affiliation(s)
- Hye-Jin Yoon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Ji Yong Kang
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Bunzo Mikami
- Laboratory of Quality Design and Exploitation, Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Kyoto 611-0011, Japan
| | - Hyung Ho Lee
- Department of Bio and Nano Chemistry, Kookmin University, Seoul 136-702, Korea
- Department of Integrative Biomedical Science and Engineering, Kookmin University, Seoul 136-702, Korea
| | - Se Won Suh
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
- Department of Biophysics and Chemical Biology, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
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38
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Edwards TE, Leibly DJ, Bhandari J, Statnekov JB, Phan I, Dieterich SH, Abendroth J, Staker BL, Van Voorhis WC, Myler PJ, Stewart LJ. Structures of phosphopantetheine adenylyltransferase from Burkholderia pseudomallei. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:1032-7. [PMID: 21904046 PMCID: PMC3169398 DOI: 10.1107/s1744309111004349] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 02/04/2011] [Indexed: 11/10/2022]
Abstract
Phosphopantetheine adenylyltransferase (PPAT) catalyzes the fourth of five steps in the coenzyme A biosynthetic pathway, reversibly transferring an adenylyl group from ATP onto 4'-phosphopantetheine to yield dephospho-coenzyme A and pyrophosphate. Burkholderia pseudomallei is a soil- and water-borne pathogenic bacterium and the etiologic agent of melioidosis, a potentially fatal systemic disease present in southeast Asia. Two crystal structures are presented of the PPAT from B. pseudomallei with the expectation that, because of the importance of the enzyme in coenzyme A biosynthesis, they will aid in the search for defenses against this pathogen. A crystal grown in ammonium sulfate yielded a 2.1 Å resolution structure that contained dephospho-coenzyme A with partial occupancy. The overall structure and ligand-binding interactions are quite similar to other bacterial PPAT crystal structures. A crystal grown at low pH in the presence of coenzyme A yielded a 1.6 Å resolution structure in the same crystal form. However, the experimental electron density was not reflective of fully ordered coenzyme A, but rather was only reflective of an ordered 4'-diphosphopantetheine moiety.
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Affiliation(s)
- Thomas E Edwards
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), USA.
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39
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Wubben T, Mesecar AD. Structure of Mycobacterium tuberculosis phosphopantetheine adenylyltransferase in complex with the feedback inhibitor CoA reveals only one active-site conformation. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:541-5. [PMID: 21543857 PMCID: PMC3087636 DOI: 10.1107/s1744309111010761] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 03/23/2011] [Indexed: 11/10/2022]
Abstract
Phosphopantetheine adenylyltransferase (PPAT) catalyzes the penultimate step in the coenzyme A (CoA) biosynthetic pathway, reversibly transferring an adenylyl group from ATP to 4'-phosphopantetheine to form dephosphocoenzyme A (dPCoA). To complement recent biochemical and structural studies on Mycobacterium tuberculosis PPAT (MtPPAT) and to provide further insight into the feedback regulation of MtPPAT by CoA, the X-ray crystal structure of the MtPPAT enzyme in complex with CoA was determined to 2.11 Å resolution. Unlike previous X-ray crystal structures of PPAT-CoA complexes from other bacteria, which showed two distinct CoA conformations bound to the active site, only one conformation of CoA is observed in the MtPPAT-CoA complex.
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Affiliation(s)
- T. Wubben
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, USA
| | - A. D. Mesecar
- Departments of Biological Sciences and Chemistry, Purdue University, West Lafayette, Indiana, USA
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40
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Cheng CS, Chen CH, Luo YC, Chen WT, Chang SY, Lyu PC, Kao MC, Yin HS. Crystal structure and biophysical characterisation of Helicobacter pylori phosphopantetheine adenylyltransferase. Biochem Biophys Res Commun 2011; 408:356-61. [PMID: 21527250 DOI: 10.1016/j.bbrc.2011.04.058] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 04/12/2011] [Indexed: 12/11/2022]
Abstract
Helicobacter pylori is a bacterium that causes chronic active gastritis and peptic ulcers. Drugs targeting H. pylori phosphopantetheine adenylyltransferase (HpPPAT), which is involved in CoA biosynthesis, may be useful. Herein, we report the expression in Escherichia coli and purification of recombinant HpPPAT and describe a crystal structure for an HpPPAT/CoA complex. As is the case for E. coli PPAT (EcPPAT), HpPPAT is hexameric in solution and as a crystal. Each protomer has a well-packed dinucleotide-binding fold in which CoA binds. Structural characterisation demonstrated that CoA derived from the E. coli expression system bound tightly to HpPPAT, presumably to initiate feedback inhibition. However, the interactions between the active-site residues of HpPPAT and CoA are not identical to those of other PPATs. Finally, CoA binding affects HpPPAT thermal denaturation.
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Affiliation(s)
- Chao-Sheng Cheng
- Institute of Bioinformatics and Structural Biology, College of Life Sciences, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
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Dessailly BH, Redfern OC, Cuff AL, Orengo CA. Detailed analysis of function divergence in a large and diverse domain superfamily: toward a refined protocol of function classification. Structure 2011; 18:1522-35. [PMID: 21070951 DOI: 10.1016/j.str.2010.08.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 08/06/2010] [Accepted: 08/13/2010] [Indexed: 10/18/2022]
Abstract
Some superfamilies contain large numbers of protein domains with very different functions. The ability to refine the functional classification of domains within these superfamilies is necessary for better understanding the evolution of functions and to guide function prediction of new relatives. To achieve this, a suitable starting point is the detailed analysis of functional divisions and mechanisms of functional divergence in a single superfamily. Here, we present such a detailed analysis in the superfamily of HUP domains. A biologically meaningful functional classification of HUP domains is obtained manually. Mechanisms of function diversification are investigated in detail using this classification. We observe that structural motifs play an important role in shaping broad functional divergence, whereas residue-level changes shape diversity at a more specific level. In parallel we examine the ability of an automated protocol to capture the biologically meaningful classification, with a view to automatically extending this classification in the future.
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Affiliation(s)
- Benoit H Dessailly
- Department of Structural and Molecular Biology, University College of London, Gower Street, London WC1E6BT, UK.
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42
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Timofeev VI, Smirnova EA, Chupova LA, Esipov RS, Kuranova IP. Preparation of the Crystal Complex of Phosphopantetheine Adenylyltransferase from Mycobacterium tuberculosis with Coenzyme A and Investigation of Its Three-Dimensional Structure at 2.1-Å Resolution. CRYSTALLOGR REP+ 2010. [DOI: 10.1134/s1063774510060234] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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43
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Wubben TJ, Mesecar AD. Kinetic, thermodynamic, and structural insight into the mechanism of phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis. J Mol Biol 2010; 404:202-19. [PMID: 20851704 DOI: 10.1016/j.jmb.2010.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 08/23/2010] [Accepted: 09/01/2010] [Indexed: 11/30/2022]
Abstract
Phosphopantetheine adenylyltransferase (PPAT) catalyzes the penultimate step in the coenzyme A (CoA) biosynthetic pathway, reversibly transferring an adenylyl group from ATP to 4'-phosphopantetheine (PhP) to form dephosphocoenzyme A. This reaction sits at the branch point between the de novo pathway and the salvage pathway, and has been shown to be a rate-limiting step in the biosynthesis of CoA. Importantly, bacterial and mammalian PPATs share little sequence homology, making the enzyme a potential target for antibiotic development. A series of steady-state kinetic, product inhibition, and direct binding studies with Mycobacterium tuberculosis PPAT (MtPPAT) was conducted and suggests that the enzyme utilizes a nonrapid-equilibrium random bi-bi mechanism. The kinetic response of MtPPAT to the binding of ATP was observed to be sigmoidal under fixed PhP concentrations, but substrate inhibition was observed at high PhP concentrations under subsaturating ATP concentrations, suggesting a preferred pathway to ternary complex formation. Negative cooperativity in the kinetic response of MtPPAT to PhP binding was observed under certain conditions and confirmed thermodynamically by isothermal titration calorimetry, suggesting the formation of an asymmetric quaternary structure during sequential ligation of substrates. Asymmetry in binding was also observed in isothermal titration calorimetry experiments with dephosphocoenzyme A and CoA. X-ray structures of MtPPAT in complex with PhP and the nonhydrolyzable ATP analogue adenosine-5'-[(α,β)-methyleno]triphosphate were solved to 1.57 Å and 2.68 Å, respectively. These crystal structures reveal small conformational changes in enzyme structure upon ligand binding, which may play a role in the nonrapid-equilibrium mechanism. We suggest that the proposed kinetic mechanism and asymmetric character in MtPPAT ligand binding may provide a means of reaction and pathway regulation in addition to that of the previously determined CoA feedback.
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Affiliation(s)
- Thomas J Wubben
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA
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The use of biochemical and biophysical tools for triage of high-throughput screening hits - A case study with Escherichia coli phosphopantetheine adenylyltransferase. Chem Biol Drug Des 2010; 75:444-54. [PMID: 20486930 DOI: 10.1111/j.1747-0285.2010.00957.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
High-throughput screening is utilized by pharmaceutical researchers and, increasingly, academic investigators to identify agents that act upon enzymes, receptors, and cellular processes. Screening hits include molecules that specifically bind the target and a greater number of non-specific compounds. It is necessary to 'triage' these hits to identify the subset worthy of further exploration. As part of our antibacterial drug discovery effort, we applied a suite of biochemical and biophysical tools to accelerate the triage process. We describe application of these tools to a series of 9-oxo-4,9-dihydropyrazolo[5,1-b]quinazoline-2-carboxylic acids (PQ) hits from a screen of Escherichia coli phosphopantetheine adenylyltransferase (PPAT). Initial confirmation of specific binding to phosphopantetheine adenylyltransferase was obtained using biochemical and biophysical tools, including a novel orthogonal assay, isothermal titration calorimetry, and saturation transfer difference NMR. To identify the phosphopantetheine adenylyltransferase sub-site bound by these inhibitors, two techniques were utilized: steady-state enzyme kinetics and a novel (19)F NMR method in which fluorine-containing fragments that bind the ATP and/or phosphopantetheine sites serve as competitive reporter probes. These data are consistent with PQs binding the ATP sub-site. In addition to identification of a series of PPAT inhibitors, the described hit triage process is broadly applicable to other enzyme targets in which milligram quantities of purified target protein are available.
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Herguedas B, Martínez-Júlvez M, Frago S, Medina M, Hermoso JA. Oligomeric state in the crystal structure of modular FAD synthetase provides insights into its sequential catalysis in prokaryotes. J Mol Biol 2010; 400:218-30. [PMID: 20471397 DOI: 10.1016/j.jmb.2010.05.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 05/03/2010] [Accepted: 05/07/2010] [Indexed: 10/19/2022]
Abstract
The crystal structure of the modular flavin adenine dinucleotide (FAD) synthetase from Corynebacterium ammoniagenes has been solved at 1.95 A resolution. The structure of C. ammoniagenes FAD synthetase presents two catalytic modules-a C-terminus with ATP-riboflavin kinase activity and an N-terminus with ATP-flavin mononucleotide (FMN) adenylyltransferase activity-that are responsible for the synthesis of FAD from riboflavin in two sequential steps. In the monomeric structure, the active sites from both modules are placed 40 A away, preventing the direct transfer of the product from the first reaction (FMN) to the second catalytic site, where it acts as substrate. Crystallographic and biophysical studies revealed a hexameric assembly formed by the interaction of two trimers. Each trimer presents a head-tail configuration, with FMN adenylyltransferase and riboflavin kinase modules from different protomers approaching the active sites and allowing the direct transfer of FMN. Experimental results provide molecular-level evidences of the mechanism of the synthesis of FMN and FAD in prokaryotes in which the oligomeric state could be involved in the regulation of the catalytic efficiency of the modular enzyme.
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Affiliation(s)
- Beatriz Herguedas
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
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Lee J, Johnson J, Ding Z, Paetzel M, Cornell RB. Crystal structure of a mammalian CTP: phosphocholine cytidylyltransferase catalytic domain reveals novel active site residues within a highly conserved nucleotidyltransferase fold. J Biol Chem 2009; 284:33535-48. [PMID: 19783652 PMCID: PMC2785197 DOI: 10.1074/jbc.m109.053363] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 09/11/2009] [Indexed: 11/06/2022] Open
Abstract
CTP:phosphocholine cytidylyltransferase (CCT) is the key regulatory enzyme in the synthesis of phosphatidylcholine, the most abundant phospholipid in eukaryotic cell membranes. The CCT-catalyzed transfer of a cytidylyl group from CTP to phosphocholine to form CDP-choline is regulated by a membrane lipid-dependent mechanism imparted by its C-terminal membrane binding domain. We present the first analysis of a crystal structure of a eukaryotic CCT. A deletion construct of rat CCTalpha spanning residues 1-236 (CCT236) lacks the regulatory domain and as a result displays constitutive activity. The 2.2-A structure reveals a CCT236 homodimer in complex with the reaction product, CDP-choline. Each chain is composed of a complete catalytic domain with an intimately associated N-terminal extension, which together with the catalytic domain contributes to the dimer interface. Although the CCT236 structure reveals elements involved in binding cytidine that are conserved with other members of the cytidylyltransferase superfamily, it also features nonconserved active site residues, His-168 and Tyr-173, that make key interactions with the beta-phosphate of CDP-choline. Mutagenesis and kinetic analyses confirmed their role in phosphocholine binding and catalysis. These results demonstrate structural and mechanistic differences in a broadly conserved protein fold across the cytidylyltransferase family. Comparison of the CCT236 structure with those of other nucleotidyltransferases provides evidence for substrate-induced active site loop movements and a disorder-to-order transition of a loop element in the catalytic mechanism.
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Affiliation(s)
- Jaeyong Lee
- From the Departments of Molecular Biology and Biochemistry and
| | - Joanne Johnson
- From the Departments of Molecular Biology and Biochemistry and
| | - Ziwei Ding
- From the Departments of Molecular Biology and Biochemistry and
| | - Mark Paetzel
- From the Departments of Molecular Biology and Biochemistry and
| | - Rosemary B. Cornell
- From the Departments of Molecular Biology and Biochemistry and
- Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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Lee HH, Yoon HJ, Kang JY, Park JH, Kim DJ, Choi KH, Lee SK, Song J, Kim HJ, Suh SW. The structure of Staphylococcus aureus phosphopantetheine adenylyltransferase in complex with 3'-phosphoadenosine 5'-phosphosulfate reveals a new ligand-binding mode. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:987-91. [PMID: 19851003 DOI: 10.1107/s1744309109036616] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 09/10/2009] [Indexed: 11/10/2022]
Abstract
Bacterial phosphopantetheine adenylyltransferase (PPAT) catalyzes the penultimate step in the coenzyme A (CoA) biosynthetic pathway. It catalyzes the reversible transfer of an adenylyl group from ATP to 4'-phosphopantetheine (Ppant) to form dephospho-CoA (dPCoA) and pyrophosphate. Previous structural studies have revealed how several ligands are recognized by bacterial PPATs. ATP, ADP, Ppant and dPCoA bind to the same binding site in a highly similar manner, while CoA binds to a partially overlapping site in a different mode. To provide further structural insights into ligand binding, the crystal structure of Staphylococcus aureus PPAT was solved in a binary complex with 3'-phosphoadenosine 5'-phosphosulfate (PAPS). This study unexpectedly revealed a new mode of ligand binding to PPAT, thus providing potentially useful information for structure-based discovery of inhibitors of bacterial PPATs.
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Affiliation(s)
- Hyung Ho Lee
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742, Republic of Korea
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Frago S, Velázquez-Campoy A, Medina M. The puzzle of ligand binding to Corynebacterium ammoniagenes FAD synthetase. J Biol Chem 2009; 284:6610-9. [PMID: 19136717 PMCID: PMC2652324 DOI: 10.1074/jbc.m808142200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 12/11/2008] [Indexed: 11/06/2022] Open
Abstract
In bacteria, riboflavin phosphorylation and subsequent conversion of FMN into FAD are carried out by FAD synthetase, a single bifunctional enzyme. Both reactions require ATP and Mg(2+). The N-terminal domain of FAD synthetase appears to be responsible for the adenylyltransferase activity, whereas the C-terminal domain would be in charge of the kinase activity. Binding to Corynebacterium ammoniagenes FAD synthetase of its products and substrates, as well as of several analogues, is analyzed. Binding parameters for adenine nucleotides to each one of the two adenine nucleotide sites are reported. In addition, it is demonstrated for the first time that the enzyme presents two independent flavin sites, each one related with one of the enzymatic activities. The binding parameters of flavins to these sites are also provided. The presence of Mg(2+) and of both adenine nucleotides and flavins cooperatively modulates the interaction parameters for the other ligands. Our data also suggest that during its double catalytic cycle FAD synthetase must suffer conformational changes induced by adenine nucleotide-Mg(2+) or flavin binding. They might include not only rearrangement of the different protein loops but also alternative conformations between domains.
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Affiliation(s)
- Susana Frago
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, and Institute of Biocomputation and Physics of Complex Systems
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Frago S, Martínez-Júlvez M, Serrano A, Medina M. Structural analysis of FAD synthetase from Corynebacterium ammoniagenes. BMC Microbiol 2008; 8:160. [PMID: 18811972 PMCID: PMC2573891 DOI: 10.1186/1471-2180-8-160] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Accepted: 09/23/2008] [Indexed: 11/21/2022] Open
Abstract
Background The prokaryotic FAD synthetase family – a group of bifunctional enzymes that catalyse riboflavin phosphorylation and FMN adenylylation within a single polypeptide chain- was analysed in terms of sequence and structure. Results Sequences of nearly 800 prokaryotic species were aligned. Those related with bifunctional FAD synthetase activities showed conservation of several consensus regions and highly conserved residues. A 3D model for the FAD synthetase from Corynebacterium ammoniagenes (CaFADS) was generated. This model confirms that the N-terminal and C-terminal domains are related to nucleotydyltransferases and riboflavin kinases, respectively. Models for the interaction of CaFADS with its substrates were also produced, allowing location of all the protein substrates in their putative binding pockets. These include two independent flavin binding sites for each CaFADS activity. Conclusion For the first time, the putative presence of a flavin binding site for the adenylylation activity, independent from that related with the phosphorylation activity, is shown. Additionally, these models suggest the functional relevance of some residues putatively involved in the catalytic processes. Their relevant roles were analysed by site-directed mutagenesis. A role was confirmed for H28, H31, S164 and T165 in the stabilisation of the P groups and the adenine moiety of ATP and, the P of FMN for the adenylylation. Similarly, T208, N210 and E268 appear critical for accommodation of the P groups of ATP and the ribityl end of RF in the active site for the phosphorylation process. Finally, the C-terminal domain was shown to catalyse the phosphorylation process on its own, but no reaction at all was observed with the individually expressed N-terminal domain.
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Affiliation(s)
- Susana Frago
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias and Institute of Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Zaragoza, Spain.
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Rubio S, Whitehead L, Larson TR, Graham IA, Rodriguez PL. The coenzyme a biosynthetic enzyme phosphopantetheine adenylyltransferase plays a crucial role in plant growth, salt/osmotic stress resistance, and seed lipid storage. PLANT PHYSIOLOGY 2008; 148:546-56. [PMID: 18621975 PMCID: PMC2528120 DOI: 10.1104/pp.108.124057] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 07/07/2008] [Indexed: 05/22/2023]
Abstract
Coenzyme A (CoA) is an essential cofactor in the metabolism of both prokaryotic and eukaryotic organisms and a universal five-step pathway is utilized to synthesize CoA from pantothenate. Null mutations in two of the five steps of this pathway led to embryo lethality and therefore viable reduction-of-function mutations are required to further study its role in plant biology. In this article, we have characterized a viable Arabidopsis (Arabidopsis thaliana) T-DNA mutant affected in the penultimate step of the CoA biosynthesis pathway, which is catalyzed by the enzyme phosphopantetheine adenylyltransferase (PPAT). This ppat-1 knockdown mutation showed an approximately 90% reduction in PPAT transcript levels and was severely impaired in plant growth and seed production. The sum of CoA and acetyl-CoA levels was severely reduced (60%-80%) in ppat-1 seedlings compared to wild type, and catabolism of storage lipids during seedling establishment was delayed. Conversely, PPAT overexpressing lines showed, on average, approximately 1.6-fold higher levels of CoA + acetyl-CoA levels, as well as enhanced vegetative and reproductive growth and salt/osmotic stress resistance. Interestingly, dry seeds of overexpressing lines contained between 35% to 50% more fatty acids than wild type, which suggests that CoA biosynthesis plays a crucial role in storage oil accumulation. Finally, biochemical analysis of the recombinant PPAT enzyme revealed an inhibitory effect of CoA on PPAT activity. Taken together, these results suggest that the reaction catalyzed by PPAT is a regulatory step in the CoA biosynthetic pathway that plays a key role for plant growth, stress resistance, and seed lipid storage.
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Affiliation(s)
- Silvia Rubio
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia/Consejo Superior de Investigaciones Científicas, ES-46022 Valencia, Spain
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