1
|
Buyachuihan L, Stegemann F, Grininger M. How Acyl Carrier Proteins (ACPs) Direct Fatty Acid and Polyketide Biosynthesis. Angew Chem Int Ed Engl 2024; 63:e202312476. [PMID: 37856285 DOI: 10.1002/anie.202312476] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 10/21/2023]
Abstract
Megasynthases, such as type I fatty acid and polyketide synthases (FASs and PKSs), are multienzyme complexes responsible for producing primary metabolites and complex natural products. Fatty acids (FAs) and polyketides (PKs) are built by assembling and modifying small acyl moieties in a stepwise manner. A central aspect of FA and PK biosynthesis involves the shuttling of substrates between the domains of the multienzyme complex. This essential process is mediated by small acyl carrier proteins (ACPs). The ACPs must navigate to the different catalytic domains within the multienzyme complex in a particular order to guarantee the fidelity of the biosynthesis pathway. However, the precise mechanisms underlying ACP-mediated substrate shuttling, particularly the factors contributing to the programming of the ACP movement, still need to be fully understood. This Review illustrates the current understanding of substrate shuttling, including concepts of conformational and specificity control, and proposes a confined ACP movement within type I megasynthases.
Collapse
Affiliation(s)
- Lynn Buyachuihan
- Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| | - Franziska Stegemann
- Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| | - Martin Grininger
- Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| |
Collapse
|
2
|
Gu T, Lu H, Liu H, Zhang G, Wang Y. Function discovery of a non-ribosomal peptide synthetase-like encoding gene in the nematode-trapping fungus Arthrobotrys oligospora. Front Microbiol 2023; 14:1210288. [PMID: 37520361 PMCID: PMC10373296 DOI: 10.3389/fmicb.2023.1210288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 06/27/2023] [Indexed: 08/01/2023] Open
Abstract
In this study, the function of a non-ribosomal peptide synthetase-like (NRPS-like) encoding gene AOL_s00188g306 (g306) was investigated to reveal the association between NRPS and nematocidal activity in the nematode-trapping fungus Arthrobotrys oligospora. Sequence analysis indicated that the encoded product of g306 is an adenylation domain of non-ribosomal peptide synthetases and extended short-chain dehydrogenase/reductase domain-containing proteins, and displays a wide substrate spectrum. The Δg306 mutants were more sensitive to chemical stressors than the wild type. Disruption of g306 impeded the nematocidal efficiency of A. oligospora. Metabolomics analysis showed that secondary metabolite biosynthesis and lipid metabolism were altered in the mutants. The phenotypic changes in the mutants can be attributed to the down-regulation of various metabolites, including fatty acyls, prenol lipids, steroidsand steroid derivative, and amino acid derivatives, identified in the present study. This study investigated the association between the non-ribosomal polypeptide-encoding gene g306 and nematicidal activity in A. oligospora, providing a reference for resolving the predation mechanism of nematode-trapping fungus.
Collapse
Affiliation(s)
- Tiantian Gu
- School of Life Sciences, Anhui University, Hefei, Anhui, China
- Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, Anhui, China
| | - Hengqian Lu
- School of Life Sciences, Anhui University, Hefei, Anhui, China
- Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, Anhui, China
| | - Huiwen Liu
- School of Life Sciences, Anhui University, Hefei, Anhui, China
- Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, Anhui, China
| | - Guanghui Zhang
- School of Life Sciences, Anhui University, Hefei, Anhui, China
- Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, Anhui, China
| | - Yongzhong Wang
- School of Life Sciences, Anhui University, Hefei, Anhui, China
- Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei, Anhui, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei, Anhui, China
| |
Collapse
|
3
|
Bon C, Cabantous S, Julien S, Guillet V, Chalut C, Rima J, Brison Y, Malaga W, Sanchez-Dafun A, Gavalda S, Quémard A, Marcoux J, Waldo GS, Guilhot C, Mourey L. Solution structure of the type I polyketide synthase Pks13 from Mycobacterium tuberculosis. BMC Biol 2022; 20:147. [PMID: 35729566 PMCID: PMC9210659 DOI: 10.1186/s12915-022-01337-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/25/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Type I polyketide synthases (PKSs) are multifunctional enzymes responsible for the biosynthesis of a group of diverse natural compounds with biotechnological and pharmaceutical interest called polyketides. The diversity of polyketides is impressive despite the limited set of catalytic domains used by PKSs for biosynthesis, leading to considerable interest in deciphering their structure-function relationships, which is challenging due to high intrinsic flexibility. Among nineteen polyketide synthases encoded by the genome of Mycobacterium tuberculosis, Pks13 is the condensase required for the final condensation step of two long acyl chains in the biosynthetic pathway of mycolic acids, essential components of the cell envelope of Corynebacterineae species. It has been validated as a promising druggable target and knowledge of its structure is essential to speed up drug discovery to fight against tuberculosis. RESULTS We report here a quasi-atomic model of Pks13 obtained using small-angle X-ray scattering of the entire protein and various molecular subspecies combined with known high-resolution structures of Pks13 domains or structural homologues. As a comparison, the low-resolution structures of two other mycobacterial polyketide synthases, Mas and PpsA from Mycobacterium bovis BCG, are also presented. This study highlights a monomeric and elongated state of the enzyme with the apo- and holo-forms being identical at the resolution probed. Catalytic domains are segregated into two parts, which correspond to the condensation reaction per se and to the release of the product, a pivot for the enzyme flexibility being at the interface. The two acyl carrier protein domains are found at opposite sides of the ketosynthase domain and display distinct characteristics in terms of flexibility. CONCLUSIONS The Pks13 model reported here provides the first structural information on the molecular mechanism of this complex enzyme and opens up new perspectives to develop inhibitors that target the interactions with its enzymatic partners or between catalytic domains within Pks13 itself.
Collapse
Affiliation(s)
- Cécile Bon
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.
| | - Stéphanie Cabantous
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Los Alamos National Laboratory, Bioscience Division B-N2, Los Alamos, NM, 87545, USA.,Present address: Centre de Recherche en Cancérologie de Toulouse (CRCT), Inserm, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sylviane Julien
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Valérie Guillet
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Christian Chalut
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Julie Rima
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yoann Brison
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Present address: Toulouse White Biotechnology, 31400, Toulouse, France
| | - Wladimir Malaga
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Angelique Sanchez-Dafun
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sabine Gavalda
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Present address: Carbios, Biopole Clermont Limagne, 63360, Saint-Beauzire, France
| | - Annaïk Quémard
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Julien Marcoux
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Geoffrey S Waldo
- Los Alamos National Laboratory, Bioscience Division B-N2, Los Alamos, NM, 87545, USA
| | - Christophe Guilhot
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.
| |
Collapse
|
4
|
Skellam E. Biosynthesis of fungal polyketides by collaborating and trans-acting enzymes. Nat Prod Rep 2022; 39:754-783. [PMID: 34842268 DOI: 10.1039/d1np00056j] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Covering: 1999 up to 2021Fungal polyketides encompass a range of structurally diverse molecules with a wide variety of biological activities. The giant multifunctional enzymes that synthesize polyketide backbones remain enigmatic, as do many of the tailoring enzymes involved in functional modifications. Recent advances in elucidating biosynthetic gene clusters (BGCs) have revealed numerous examples of fungal polyketide synthases that require the action of collaborating enzymes to synthesize the carbon backbone. This review will discuss collaborating and trans-acting enzymes involved in loading, extending, and releasing polyketide intermediates from fungal polyketide synthases, and additional modifications introduced by trans-acting enzymes demonstrating the complexity encountered when investigating natural product biosynthesis in fungi.
Collapse
Affiliation(s)
- Elizabeth Skellam
- Department of Chemistry, BioDiscovery Institute, University of North Texas, 1155 Union Circle, Denton, TX 76203, USA.
| |
Collapse
|
5
|
Pedersen TB, Nielsen MR, Kristensen SB, Spedtsberg EML, Sørensen T, Petersen C, Muff J, Sondergaard TE, Nielsen KL, Wimmer R, Gardiner DM, Sørensen JL. Speed dating for enzymes! Finding the perfect phosphopantetheinyl transferase partner for your polyketide synthase. Microb Cell Fact 2022; 21:9. [PMID: 35012550 PMCID: PMC8751348 DOI: 10.1186/s12934-021-01734-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/29/2021] [Indexed: 11/24/2022] Open
Abstract
The biosynthetic pathways for the fungal polyketides bikaverin and bostrycoidin, from Fusarium verticillioides and Fusarium solani respectively, were reconstructed and heterologously expressed in S. cerevisiae alongside seven different phosphopantetheinyl transferases (PPTases) from a variety of origins spanning bacterial, yeast and fungal origins. In order to gauge the efficiency of the interaction between the ACP-domains of the polyketide synthases (PKS) and PPTases, each were co-expressed individually and the resulting production of target polyketides were determined after 48 h of growth. In co-expression with both biosynthetic pathways, the PPTase from Fusarium verticillioides (FvPPT1) proved most efficient at producing both bikaverin and bostrycoidin, at 1.4 mg/L and 5.9 mg/L respectively. Furthermore, the remaining PPTases showed the ability to interact with both PKS's, except for a single PKS-PPTase combination. The results indicate that it is possible to boost the production of a target polyketide, simply by utilizing a more optimal PPTase partner, instead of the commonly used PPTases; NpgA, Gsp and Sfp, from Aspergillus nidulans, Brevibacillus brevis and Bacillus subtilis respectively.
Collapse
Affiliation(s)
- Tobias Bruun Pedersen
- Department of Chemistry and Bioscience, Aalborg University Esbjerg, Niels Bohrs Vej 8, 6700, Esbjerg, Denmark
| | - Mikkel Rank Nielsen
- Department of Chemistry and Bioscience, Aalborg University Esbjerg, Niels Bohrs Vej 8, 6700, Esbjerg, Denmark
| | | | - Eva Mie Lang Spedtsberg
- Department of Chemistry and Bioscience, Aalborg University Esbjerg, Niels Bohrs Vej 8, 6700, Esbjerg, Denmark
| | - Trine Sørensen
- Department of Chemistry and Bioscience, Aalborg University Aalborg, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark
| | - Celine Petersen
- Department of Chemistry and Bioscience, Aalborg University Aalborg, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark
| | - Jens Muff
- Department of Chemistry and Bioscience, Aalborg University Esbjerg, Niels Bohrs Vej 8, 6700, Esbjerg, Denmark
| | - Teis Esben Sondergaard
- Department of Chemistry and Bioscience, Aalborg University Aalborg, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark
| | - Kåre Lehmann Nielsen
- Department of Chemistry and Bioscience, Aalborg University Aalborg, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark
| | - Reinhard Wimmer
- Department of Chemistry and Bioscience, Aalborg University Aalborg, Fredrik Bajers Vej 7H, 9220, Aalborg, Denmark
| | - Donald Max Gardiner
- The University of Queensland, 306 Carmody Rd, St Lucia, Brisbane, QLD, 4072, Australia
| | - Jens Laurids Sørensen
- Department of Chemistry and Bioscience, Aalborg University Esbjerg, Niels Bohrs Vej 8, 6700, Esbjerg, Denmark.
| |
Collapse
|
6
|
Thongkawphueak T, Winter AJ, Williams C, Maple HJ, Soontaranon S, Kaewhan C, Campopiano DJ, Crump MP, Wattana-Amorn P. Solution Structure and Conformational Dynamics of a Doublet Acyl Carrier Protein from Prodigiosin Biosynthesis. Biochemistry 2021; 60:219-230. [PMID: 33416314 DOI: 10.1021/acs.biochem.0c00830] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The acyl carrier protein (ACP) is an indispensable component of both fatty acid and polyketide synthases and is primarily responsible for delivering acyl intermediates to enzymatic partners. At present, increasing numbers of multidomain ACPs have been discovered with roles in molecular recognition of trans-acting enzymatic partners as well as increasing metabolic flux. Further structural information is required to provide insight into their function, yet to date, the only high-resolution structure of this class to be determined is that of the doublet ACP (two continuous ACP domains) from mupirocin synthase. Here we report the solution nuclear magnetic resonance (NMR) structure of the doublet ACP domains from PigH (PigH ACP1-ACP2), which is an enzyme that catalyzes the formation of the bipyrrolic intermediate of prodigiosin, a potent anticancer compound with a variety of biological activities. The PigH ACP1-ACP2 structure shows each ACP domain consists of three conserved helices connected by a linker that is partially restricted by interactions with the ACP1 domain. Analysis of the holo (4'-phosphopantetheine, 4'-PP) form of PigH ACP1-ACP2 by NMR revealed conformational exchange found predominantly in the ACP2 domain reflecting the inherent plasticity of this ACP. Furthermore, ensemble models obtained from SAXS data reveal two distinct conformers, bent and extended, of both apo (unmodified) and holo PigH ACP1-ACP2 mediated by the central linker. The bent conformer appears to be a result of linker-ACP1 interactions detected by NMR and might be important for intradomain communication during the biosynthesis. These results provide new insights into the behavior of the interdomain linker of multiple ACP domains that may modulate protein-protein interactions. This is likely to become an increasingly important consideration for metabolic engineering in prodigiosin and other related biosynthetic pathways.
Collapse
Affiliation(s)
- Thitapa Thongkawphueak
- Department of Chemistry, Special Research Unit for Advanced Magnetic Resonance and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Ashley J Winter
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Christopher Williams
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K.,BrisSynBio, Centre for Synthetic Biology Research, Life Sciences Building, Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, U.K
| | - Hannah J Maple
- School of Social and Community Medicine, University of Bristol, Oakfield House, Bristol BS8 2BN, U.K
| | - Siriwat Soontaranon
- Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima 30000, Thailand
| | - Chonthicha Kaewhan
- Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima 30000, Thailand
| | - Dominic J Campopiano
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Matthew P Crump
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K.,BrisSynBio, Centre for Synthetic Biology Research, Life Sciences Building, Tyndall Avenue, University of Bristol, Bristol BS8 1TQ, U.K
| | - Pakorn Wattana-Amorn
- Department of Chemistry, Special Research Unit for Advanced Magnetic Resonance and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| |
Collapse
|
7
|
Bunnak W, Winter AJ, Lazarus CM, Crump MP, Race PR, Wattana-Amorn P. SAXS reveals highly flexible interdomain linkers of tandem acyl carrier protein-thioesterase domains from a fungal nonreducing polyketide synthase. FEBS Lett 2020; 595:133-144. [PMID: 33043457 DOI: 10.1002/1873-3468.13954] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 10/01/2020] [Accepted: 10/05/2020] [Indexed: 11/07/2022]
Abstract
Menisporopsin A is a fungal bioactive macrocyclic polylactone, the biosynthesis of which requires only reducing (R) and nonreducing (NR) polyketide synthases (PKSs) to guide a series of esterification and cyclolactonization reactions. There is no structural information pertaining to these PKSs. Here, we report the solution characterization of singlet and doublet acyl carrier protein (ACP2 and ACP1 -ACP2 )-thioesterase (TE) domains from NR-PKS involved in menisporopsin A biosynthesis. Small-angle X-ray scattering (SAXS) studies in combination with homology modelling reveal that these polypeptides adopt a distinctive beads-on-a-string configuration, characterized by the presence of highly flexible interdomain linkers. These models provide a platform for studying domain organization and interdomain interactions in fungal NR-PKSs, which may be of value in directing the design of functionally optimized polyketide scaffolds.
Collapse
Affiliation(s)
- Waraporn Bunnak
- Department of Chemistry, Special Research Unit for Advanced Magnetic Resonance, Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | | | | | | | - Paul R Race
- School of Biochemistry, University of Bristol, UK.,BrisSynBio Synthetic Biology Research Centre, University of Bristol, UK
| | - Pakorn Wattana-Amorn
- Department of Chemistry, Special Research Unit for Advanced Magnetic Resonance, Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| |
Collapse
|
8
|
Liao J, Pang K, Sun G, Pai T, Hsu P, Lin J, Sun K, Hsieh C, Tang S. Chimeric 6-methylsalicylic acid synthase with domains of acyl carrier protein and methyltransferase from Pseudallescheria boydii shows novel biosynthetic activity. Microb Biotechnol 2019; 12:920-931. [PMID: 31199579 PMCID: PMC6681407 DOI: 10.1111/1751-7915.13445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 05/06/2019] [Accepted: 05/17/2019] [Indexed: 01/09/2023] Open
Abstract
Polyketides are important secondary metabolites, many of which exhibit potent pharmacological applications. Biosynthesis of polyketides is carried out by a single polyketide synthase (PKS) or multiple PKSs in successive elongations of enzyme-bound intermediates related to fatty acid biosynthesis. The polyketide gene PKS306 from Pseudallescheria boydii NTOU2362 containing domains of ketosynthase (KS), acyltransferase (AT), dehydratase (DH), acyl carrier protein (ACP) and methyltransferase (MT) was cloned in an attempt to produce novel chemical compounds, and this PKS harbouring green fluorescent protein (GFP) was expressed in Saccharomyces cerevisiae. Although fluorescence of GFP and fusion protein analysed by anti-GFP antibody were observed, no novel compound was detected. 6-methylsalicylic acid synthase (6MSAS) was then used as a template and engineered with PKS306 by combinatorial fusion. The chimeric PKS containing domains of KS, AT, DH and ketoreductase (KR) from 6MSAS with ACP and MT from PKS306 demonstrated biosynthesis of a novel compound. The compound was identified with a deduced chemical formula of C7 H10 O3 , and the chemical structure was named as 2-hydroxy-2-(propan-2-yl) cyclobutane-1,3-dione. The novel compound synthesized by the chimeric PKS in this study demonstrates the feasibility of combinatorial fusion of PKS genes to produce novel polyketides.
Collapse
Affiliation(s)
- Ji‐Long Liao
- Department of Bioscience and BiotechnologyCenter of Excellence for the OceansNational Taiwan Ocean UniversityNo. 2 Pei‐Ning RoadKeelung20224Taiwan
| | - Ka‐Lai Pang
- Department of Marine BiologyCenter of Excellence for the OceansNational Taiwan Ocean UniversityNo. 2 Pei‐Ning RoadKeelung20224Taiwan
| | - Guang‐Huan Sun
- Division of UrologyDepartment of SurgeryNational Defense Medical CenterTri‐Service General HospitalNo. 325, Sec. 2, Cheng‐gong Rd.TaipeiTaiwan
| | - Tun‐Wen Pai
- Department of Computer Science and EngineeringNational Taiwan Ocean UniversityNo. 2 Pei‐Ning RoadKeelung20224Taiwan
| | - Pang‐Hung Hsu
- Department of Bioscience and BiotechnologyCenter of Excellence for the OceansNational Taiwan Ocean UniversityNo. 2 Pei‐Ning RoadKeelung20224Taiwan
| | - Jyuan‐Siou Lin
- Department of Bioscience and BiotechnologyCenter of Excellence for the OceansNational Taiwan Ocean UniversityNo. 2 Pei‐Ning RoadKeelung20224Taiwan
| | - Kuang‐Hui Sun
- Department of Biotechnology and Laboratory Science in MedicineNational Yang‐Ming UniversityNo. 155, Sec. 2, Linong StreetTaipeiTaiwan
- Department of Education and ResearchTaipei City HospitalTaipeiTaiwan
| | | | - Shye‐Jye Tang
- Department of Bioscience and BiotechnologyCenter of Excellence for the OceansNational Taiwan Ocean UniversityNo. 2 Pei‐Ning RoadKeelung20224Taiwan
| |
Collapse
|
9
|
Farmer R, Thomas CM, Winn PJ. Structure, function and dynamics in acyl carrier proteins. PLoS One 2019; 14:e0219435. [PMID: 31291335 PMCID: PMC6619796 DOI: 10.1371/journal.pone.0219435] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/24/2019] [Indexed: 11/18/2022] Open
Abstract
Carrier proteins are four-helix bundles that covalently hold metabolites and secondary metabolites, such as fatty acids, polyketides and non-ribosomal peptides. These proteins mediate the production of many pharmaceutically important compounds including antibiotics and anticancer agents. Acyl carrier proteins (ACPs) can be found as part of a multi-domain polypeptide (Type I ACPs), or as part of a multiprotein complex (Type II). Here, the main focus is on ACP2 and ACP3, domains from the type I trans-AT polyketide synthase MmpA, which is a core component of the biosynthetic pathway of the antibiotic mupirocin. During molecular dynamics simulations of their apo, holo and acyl forms ACP2 and ACP3 both form a substrate-binding surface-groove. The substrates bound to this surface-groove have polar groups on their acyl chain exposed and forming hydrogen bonds with the solvent. Bulky hydrophobic residues in the GXDS motif common to all ACPs, and similar residues on helix III, appear to prohibit the formation of a deep tunnel in type I ACPs and type II ACPs from polyketide synthases. In contrast, the equivalent positions in ACPs from type II fatty acid synthases, which do form a deep solvent-excluded substrate-binding tunnel, have the small residue alanine. During simulation, ACP3 with mutations I61A L36A W44L forms a deep tunnel that can fully bury a saturated substrate in the core of the ACP, in contrast to the surface groove of the wild type ACP3. Similarly, in the ACP from E. coli fatty acid synthase, a type II ACP, mutations can change ligand binding from being inside a deep tunnel to being in a surface groove, thus demonstrating how changing a few residues can modify the possibilities for ligand binding.
Collapse
Affiliation(s)
- Rohit Farmer
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- Department of Computational Biology and Bioinformatics, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad, India
| | - Christopher Morton Thomas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- The Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Peter James Winn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- The Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- Centre for Computational Biology, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail:
| |
Collapse
|
10
|
Mehmood R, Qi HW, Steeves AH, Kulik HJ. The Protein’s Role in Substrate Positioning and Reactivity for Biosynthetic Enzyme Complexes: The Case of SyrB2/SyrB1. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00865] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
11
|
Herbst DA, Huitt-Roehl CR, Jakob RP, Kravetz JM, Storm PA, Alley JR, Townsend CA, Maier T. The structural organization of substrate loading in iterative polyketide synthases. Nat Chem Biol 2018; 14:474-479. [PMID: 29610486 DOI: 10.1038/s41589-018-0026-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/07/2018] [Indexed: 11/09/2022]
Abstract
Polyketide synthases (PKSs) are microbial multienzymes for the biosynthesis of biologically potent secondary metabolites. Polyketide production is initiated by the loading of a starter unit onto an integral acyl carrier protein (ACP) and its subsequent transfer to the ketosynthase (KS). Initial substrate loading is achieved either by multidomain loading modules or by the integration of designated loading domains, such as starter unit acyltransferases (SAT), whose structural integration into PKS remains unresolved. A crystal structure of the loading/condensing region of the nonreducing PKS CTB1 demonstrates the ordered insertion of a pseudodimeric SAT into the condensing region, which is aided by the SAT-KS linker. Cryo-electron microscopy of the post-loading state trapped by mechanism-based crosslinking of ACP to KS reveals asymmetry across the CTB1 loading/-condensing region, in accord with preferential 1:2 binding stoichiometry. These results are critical for re-engineering the loading step in polyketide biosynthesis and support functional relevance of asymmetric conformations of PKSs.
Collapse
Affiliation(s)
- Dominik A Herbst
- Department of Biozentrum, University of Basel, Basel, Switzerland
| | | | - Roman P Jakob
- Department of Biozentrum, University of Basel, Basel, Switzerland
| | - Jacob M Kravetz
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Philip A Storm
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Jamie R Alley
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Craig A Townsend
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Timm Maier
- Department of Biozentrum, University of Basel, Basel, Switzerland.
| |
Collapse
|
12
|
Sticky swinging arm dynamics: studies of an acyl carrier protein domain from the mycolactone polyketide synthase. Biochem J 2016; 473:1097-110. [PMID: 26920023 PMCID: PMC4847154 DOI: 10.1042/bcj20160041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/18/2016] [Indexed: 11/17/2022]
Abstract
When covalently linked to an acyl carrier protein (ACP) and loaded with acyl substrate-mimics, some 4′-phosphopantetheine prosthetic group arms swing freely, whereas others stick to the protein surface, suggesting a possible mode of interaction with enzyme domains during polyketide biosynthesis. Type I modular polyketide synthases (PKSs) produce polyketide natural products by passing a growing acyl substrate chain between a series of enzyme domains housed within a gigantic multifunctional polypeptide assembly. Throughout each round of chain extension and modification reactions, the substrate stays covalently linked to an acyl carrier protein (ACP) domain. In the present study we report on the solution structure and dynamics of an ACP domain excised from MLSA2, module 9 of the PKS system that constructs the macrolactone ring of the toxin mycolactone, cause of the tropical disease Buruli ulcer. After modification of apo ACP with 4′-phosphopantetheine (Ppant) to create the holo form, 15N nuclear spin relaxation and paramagnetic relaxation enhancement (PRE) experiments suggest that the prosthetic group swings freely. The minimal chemical shift perturbations displayed by Ppant-attached C3 and C4 acyl chains imply that these substrate-mimics remain exposed to solvent at the end of a flexible Ppant arm. By contrast, hexanoyl and octanoyl chains yield much larger chemical shift perturbations, indicating that they interact with the surface of the domain. The solution structure of octanoyl-ACP shows the Ppant arm bending to allow the acyl chain to nestle into a nonpolar pocket, whereas the prosthetic group itself remains largely solvent exposed. Although the highly reduced octanoyl group is not a natural substrate for the ACP from MLSA2, similar presentation modes would permit partner enzyme domains to recognize an acyl group while it is bound to the surface of its carrier protein, allowing simultaneous interactions with both the substrate and the ACP.
Collapse
|
13
|
Perez DR, Leibundgut M, Wider G. Interactions of the Acyl Chain with the Saccharomyces cerevisiae Acyl Carrier Protein. Biochemistry 2015; 54:2205-13. [DOI: 10.1021/bi5014563] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel R. Perez
- Institute
of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg
5, 8093 Zurich, Switzerland
| | - Marc Leibundgut
- Institute
of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg
5, 8093 Zurich, Switzerland
| | - Gerhard Wider
- Institute
of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg
5, 8093 Zurich, Switzerland
| |
Collapse
|
14
|
Beld J, Cang H, Burkart MD. Visualizing the chain-flipping mechanism in fatty-acid biosynthesis. Angew Chem Int Ed Engl 2014; 53:14456-61. [PMID: 25354391 PMCID: PMC4425425 DOI: 10.1002/anie.201408576] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Indexed: 11/08/2022]
Abstract
The acyl carrier protein (ACP) from fatty acid synthases sequesters elongating products within its hydrophobic core, but this dynamic mechanism remains poorly understood. We exploited solvatochromic pantetheine probes attached to ACP that fluoresce when sequestered. The addition of a catalytic partner lures the cargo out of the ACP and into the active site of the enzyme, thus enhancing fluorescence to reveal the elusive chain-flipping mechanism. This activity was confirmed by the use of a dual solvatochromic cross-linking probe and solution-phase NMR spectroscopy. The chain-flipping mechanism was visualized by single-molecule fluorescence techniques, thus demonstrating specificity between the Escherichia coli ACP and its ketoacyl synthase catalytic partner KASII.
Collapse
Affiliation(s)
- Joris Beld
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA
| | - Hu Cang
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA
| |
Collapse
|
15
|
Beld J, Cang H, Burkart MD. Visualizing the Chain-Flipping Mechanism in Fatty-Acid Biosynthesis. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201408576] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
16
|
Johnson MR, Londergan CH, Charkoudian LK. Probing the phosphopantetheine arm conformations of acyl carrier proteins using vibrational spectroscopy. J Am Chem Soc 2014; 136:11240-3. [PMID: 25080832 PMCID: PMC4140477 DOI: 10.1021/ja505442h] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Indexed: 12/23/2022]
Abstract
Acyl carrier proteins (ACPs) are universal and highly conserved domains central to both fatty acid and polyketide biosynthesis. These proteins tether reactive acyl intermediates with a swinging 4'-phosphopantetheine (Ppant) arm and interact with a suite of catalytic partners during chain transport and elongation while stabilizing the growing chain throughout the biosynthetic pathway. The flexible nature of the Ppant arm and the transient nature of ACP-enzyme interactions impose a major obstacle to obtaining structural information relevant to understanding polyketide and fatty acid biosynthesis. To overcome this challenge, we installed a thiocyanate vibrational spectroscopic probe on the terminal thiol of the ACP Ppant arm. This site-specific probe successfully reported on the local environment of the Ppant arm of two ACPs previously characterized by solution NMR, and was used to determine the solution exposure of the Ppant arm of an ACP from 6-deoxyerythronolide B synthase (DEBS). Given the sensitivity of the probe's CN stretching band to conformational distributions resolved on the picosecond time scale, this work lays a foundation for observing the dynamic action-related structural changes of ACPs using vibrational spectroscopy.
Collapse
Affiliation(s)
- Matthew
N. R. Johnson
- Department of Chemistry, Haverford College, Haverford, Pennsylvania 19041-1392, United States
| | - Casey H. Londergan
- Department of Chemistry, Haverford College, Haverford, Pennsylvania 19041-1392, United States
| | - Louise K. Charkoudian
- Department of Chemistry, Haverford College, Haverford, Pennsylvania 19041-1392, United States
| |
Collapse
|
17
|
Newman AG, Vagstad AL, Storm P, Townsend CA. Systematic domain swaps of iterative, nonreducing polyketide synthases provide a mechanistic understanding and rationale for catalytic reprogramming. J Am Chem Soc 2014; 136:7348-62. [PMID: 24815013 PMCID: PMC4046768 DOI: 10.1021/ja5007299] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Indexed: 11/29/2022]
Abstract
Iterative, nonreducing polyketide synthases (NR-PKSs) are multidomain enzymes responsible for the construction of the core architecture of aromatic polyketide natural products in fungi. Engineering these enzymes for the production of non-native metabolites has been a long-standing goal. We conducted a systematic survey of in vitro "domain swapped" NR-PKSs using an enzyme deconstruction approach. The NR-PKSs were dissected into mono- to multidomain fragments and recombined as noncognate pairs in vitro, reconstituting enzymatic activity. The enzymes used in this study produce aromatic polyketides that are representative of the four main chemical features set by the individual NR-PKS: starter unit selection, chain-length control, cyclization register control, and product release mechanism. We found that boundary conditions limit successful chemistry, which are dependent on a set of underlying enzymatic mechanisms. Crucial for successful redirection of catalysis, the rate of productive chemistry must outpace the rate of spontaneous derailment and thioesterase-mediated editing. Additionally, all of the domains in a noncognate system must interact efficiently if chemical redirection is to proceed. These observations refine and further substantiate current understanding of the mechanisms governing NR-PKS catalysis.
Collapse
Affiliation(s)
- Adam G. Newman
- Department of Chemistry, The Johns Hopkins
University, 3400 N. Charles
Street, Baltimore, Maryland 21218, United States
| | | | - Philip
A. Storm
- Department of Chemistry, The Johns Hopkins
University, 3400 N. Charles
Street, Baltimore, Maryland 21218, United States
| | - Craig A. Townsend
- Department of Chemistry, The Johns Hopkins
University, 3400 N. Charles
Street, Baltimore, Maryland 21218, United States
| |
Collapse
|
18
|
Jiménez-Osés G, Osuna S, Gao X, Sawaya MR, Gilson L, Collier SJ, Huisman GW, Yeates TO, Tang Y, Houk KN. The role of distant mutations and allosteric regulation on LovD active site dynamics. Nat Chem Biol 2014; 10:431-6. [PMID: 24727900 PMCID: PMC4028369 DOI: 10.1038/nchembio.1503] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 03/13/2014] [Indexed: 01/04/2023]
Abstract
Natural enzymes have evolved to perform their cellular functions under complex selective pressures, which often require their catalytic activities to be regulated by other proteins. We contrasted a natural enzyme, LovD, which acts on a protein-bound (LovF) acyl substrate, with a laboratory-generated variant that was transformed by directed evolution to accept instead a small free acyl thioester, and no longer requires the acyl carrier protein. The resulting 29-mutant variant is 1000-fold more efficient in the synthesis of the drug simvastatin than the wild-type LovD. This is the first non-patent report of the enzyme currently used for the manufacture of simvastatin, as well as the intermediate evolved variants. Crystal structures and microsecond molecular dynamics simulations revealed the mechanism by which the laboratory-generated mutations free LovD from dependence on protein-protein interactions. Mutations dramatically altered conformational dynamics of the catalytic residues, obviating the need for allosteric modulation by the acyl carrier LovF.
Collapse
Affiliation(s)
- Gonzalo Jiménez-Osés
- 1] Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA. [2]
| | - Sílvia Osuna
- 1] Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA. [2]
| | - Xue Gao
- 1] Department of Chemical and Biomolecular Engineering, University of California-Los Angeles, Los Angeles, California, USA. [2]
| | - Michael R Sawaya
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California, USA
| | | | | | | | - Todd O Yeates
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California, USA
| | - Yi Tang
- 1] Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA. [2] Department of Chemical and Biomolecular Engineering, University of California-Los Angeles, Los Angeles, California, USA
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California, USA
| |
Collapse
|
19
|
Zhao C, Yuan Z, Zhang Y, Ma B, Li H, Tang S, Xie X, She X. Scalable, efficient total synthesis of (+)-mupirocin H. Org Chem Front 2014. [DOI: 10.1039/c3qo00038a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
20
|
|
21
|
Haines AS, Dong X, Song Z, Farmer R, Williams C, Hothersall J, Płoskoń E, Wattana-Amorn P, Stephens ER, Yamada E, Gurney R, Takebayashi Y, Masschelein J, Cox RJ, Lavigne R, Willis CL, Simpson TJ, Crosby J, Winn PJ, Thomas CM, Crump MP. A conserved motif flags acyl carrier proteins for β-branching in polyketide synthesis. Nat Chem Biol 2013; 9:685-692. [PMID: 24056399 PMCID: PMC4658705 DOI: 10.1038/nchembio.1342] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 08/22/2013] [Indexed: 11/14/2022]
Abstract
Type I PKSs often utilise programmed β-branching, via enzymes of an “HMG-CoA synthase (HCS) cassette”, to incorporate various side chains at the second carbon from the terminal carboxylic acid of growing polyketide backbones. We identified a strong sequence motif in Acyl Carrier Proteins (ACPs) where β-branching is known. Substituting ACPs confirmed a correlation of ACP type with β-branching specificity. While these ACPs often occur in tandem, NMR analysis of tandem β-branching ACPs indicated no ACP-ACP synergistic effects and revealed that the conserved sequence motif forms an internal core rather than an exposed patch. Modelling and mutagenesis identified ACP Helix III as a probable anchor point of the ACP-HCS complex whose position is determined by the core. Mutating the core affects ACP functionality while ACP-HCS interface substitutions modulate system specificity. Our method for predicting β-carbon branching expands the potential for engineering novel polyketides and lays a basis for determining specificity rules.
Collapse
Affiliation(s)
- Anthony S Haines
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Xu Dong
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Zhongshu Song
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Rohit Farmer
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | | | - Joanne Hothersall
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Eliza Płoskoń
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | | | - Elton R Stephens
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Erika Yamada
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Rachel Gurney
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Yuiko Takebayashi
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Joleen Masschelein
- Division of Gene Technology, KU Leuven, Kasteelpark Arenberg 21 - box 2462, 3001 Heverlee, Belgium
| | - Russell J Cox
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Rob Lavigne
- Division of Gene Technology, KU Leuven, Kasteelpark Arenberg 21 - box 2462, 3001 Heverlee, Belgium
| | | | - Thomas J Simpson
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - John Crosby
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| | - Peter J Winn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Christopher M Thomas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Matthew P Crump
- School of Chemistry, Cantock's Close, Clifton, Bristol, BS8 1TS, UK
| |
Collapse
|
22
|
Probing the selectivity and protein·protein interactions of a nonreducing fungal polyketide synthase using mechanism-based crosslinkers. ACTA ACUST UNITED AC 2013; 20:1135-46. [PMID: 23993461 DOI: 10.1016/j.chembiol.2013.07.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 06/28/2013] [Accepted: 07/07/2013] [Indexed: 01/05/2023]
Abstract
Protein·protein interactions, which often involve interactions among an acyl carrier protein (ACP) and ACP partner enzymes, are important for coordinating polyketide biosynthesis. However, the nature of such interactions is not well understood, especially in the fungal nonreducing polyketide synthases (NR-PKSs) that biosynthesize toxic and pharmaceutically important polyketides. Here, we employ mechanism-based crosslinkers to successfully probe ACP and ketosynthase (KS) domain interactions in NR-PKSs. We found that crosslinking efficiency is closely correlated with the strength of ACP·KS interactions and that KS demonstrates strong starter unit selectivity. We further identified positively charged surface residues by KS mutagenesis, which mediates key interactions with the negatively charged ACP surface. Such complementary/matching contact pairs can serve as "adapter surfaces" for future efforts to generate new polyketides using NR-PKSs.
Collapse
|
23
|
Kulik HJ, Drennan CL. Substrate placement influences reactivity in non-heme Fe(II) halogenases and hydroxylases. J Biol Chem 2013; 288:11233-41. [PMID: 23449977 DOI: 10.1074/jbc.m112.415570] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
We employ error-corrected density functional theory methods to map out the dependence of reactivity on substrate position for SyrB2, a member of a family of non-heme iron halogenases and hydroxylases that are only reactive toward amino acid substrates delivered via prosthetic phosphopantetheine arms. For the initial hydrogen abstraction step, the inherent flexibility of the phosphopantetheine molecule weakens the position dependence for both the native substrate (threonine for SyrB2) and alternative substrates. Over a 5 Å window of substrate positions, the tethered hydrogen abstraction step proceeds with nearly identical activation energies and donor-acceptor distances in the transition state. The propensity of a particular substrate toward halogenation or hydroxylation is found to depend strongly on the substrate placement following hydrogen abstraction, with deeper substrate delivery into the active (for native substrates) site favoring halogenation and shallower substrate delivery favoring hydroxylation.
Collapse
Affiliation(s)
- Heather J Kulik
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | | |
Collapse
|
24
|
Xu W, Qiao K, Tang Y. Structural analysis of protein-protein interactions in type I polyketide synthases. Crit Rev Biochem Mol Biol 2012; 48:98-122. [PMID: 23249187 DOI: 10.3109/10409238.2012.745476] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Polyketide synthases (PKSs) are responsible for synthesizing a myriad of natural products with agricultural, medicinal relevance. The PKSs consist of multiple functional domains of which each can catalyze a specified chemical reaction leading to the synthesis of polyketides. Biochemical studies showed that protein-substrate and protein-protein interactions play crucial roles in these complex regio-/stereo-selective biochemical processes. Recent developments on X-ray crystallography and protein NMR techniques have allowed us to understand the biosynthetic mechanism of these enzymes from their structures. These structural studies have facilitated the elucidation of the sequence-function relationship of PKSs and will ultimately contribute to the prediction of product structure. This review will focus on the current knowledge of type I PKS structures and the protein-protein interactions in this system.
Collapse
Affiliation(s)
- Wei Xu
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
| | | | | |
Collapse
|
25
|
Abstract
The iterative type I polyketide synthases (IPKSs) are central to the biosynthesis of an enormously diverse array of natural products in fungi. These natural products, known as polyketides, exhibit a wide range of biological activities and include clinically important drugs as well as undesirable toxins. The PKSs synthesize these structurally diverse polyketides via a series of decarboxylative condensations of malonyl-CoA extender units and β-keto modifications in a highly programmed manner. Significant progress has been made over the past few years in understanding the biosynthetic mechanism and programming of fungal PKSs. The continuously expanding fungal genome sequence data have sparked genome-directed discoveries of new fungal PKSs and associated products. The increasing number of fungal PKSs that have been linked to their products along with in-depth biochemical and structural characterizations of these large enzymes have remarkably improved our knowledge on the molecular basis for polyketide structural diversity in fungi. This Perspective highlights the recent advances and examines how the newly expanded paradigm has contributed to our ability to link fungal PKS genes to chemical structures and vice versa. The knowledge will help us navigate through the logarithmically expanding seas of genomic information for polyketide compound discovery and provided opportunities to reprogram these megasynthases to generate new chemical entities.
Collapse
Affiliation(s)
- Yit-Heng Chooi
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095
| | - Yi Tang
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095
| |
Collapse
|
26
|
Crosby J, Crump MP. The structural role of the carrier protein--active controller or passive carrier. Nat Prod Rep 2012; 29:1111-37. [PMID: 22930263 DOI: 10.1039/c2np20062g] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Common to all FASs, PKSs and NRPSs is a remarkable component, the acyl or peptidyl carrier protein (A/PCP). These take the form of small individual proteins in type II systems or discrete folded domains in the multi-domain type I systems and are characterized by a fold consisting of three major α-helices and between 60-100 amino acids. This protein is central to these biosynthetic systems and it must bind and transport a wide variety of functionalized ligands as well as mediate numerous protein-protein interactions, all of which contribute to efficient enzyme turnover. This review covers the structural and biochemical characterization of carrier proteins, as well as assessing their interactions with different ligands, and other synthase components. Finally, their role as an emerging tool in biotechnology is discussed.
Collapse
Affiliation(s)
- John Crosby
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | | |
Collapse
|
27
|
Vagstad AL, Bumpus SB, Belecki K, Kelleher NL, Townsend CA. Interrogation of global active site occupancy of a fungal iterative polyketide synthase reveals strategies for maintaining biosynthetic fidelity. J Am Chem Soc 2012; 134:6865-77. [PMID: 22452347 DOI: 10.1021/ja3016389] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Nonreducing iterative polyketide synthases (NR-PKSs) are responsible for assembling the core of fungal aromatic natural products with diverse biological properties. Despite recent advances in the field, many mechanistic details of polyketide assembly by these megasynthases remain unknown. To expand our understanding of substrate loading, polyketide elongation, cyclization, and product release, active site occupancy and product output were explored by Fourier transform mass spectrometry using the norsolorinic acid anthrone-producing polyketide synthase, PksA, from the aflatoxin biosynthetic pathway in Aspergillus parasiticus. Here we report the simultaneous observation of covalent intermediates from all catalytic domains of PksA from in vitro reconstitution reactions. The data provide snapshots of iterative catalysis and reveal an underappreciated editing function for the C-terminal thioesterase domain beyond its recently established synthetic role in Claisen/Dieckmann cyclization and product release. The specificity of thioesterase catalyzed hydrolysis was explored using biosynthetically relevant protein-bound and small molecule acyl substrates and demonstrated activity against hexanoyl and acetyl, but not malonyl. Processivity of polyketide extension was supported by the inability of a nonhydrolyzable malonyl analog to trap products of intermediate chain lengths and by the detection of only fully extended species observed covalently bound to, and as the predominant products released by, PksA. High occupancy of the malonyl transacylase domain and fast relative rate of malonyl transfer compared to starter unit transfer indicate that rapid loading of extension units onto the carrier domain facilitates efficient chain extension in a manner kinetically favorable to ultimate product formation.
Collapse
Affiliation(s)
- Anna L Vagstad
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland, USA
| | | | | | | | | |
Collapse
|
28
|
Li Y, Chooi YH, Sheng Y, Valentine JS, Tang Y. Comparative characterization of fungal anthracenone and naphthacenedione biosynthetic pathways reveals an α-hydroxylation-dependent Claisen-like cyclization catalyzed by a dimanganese thioesterase. J Am Chem Soc 2011; 133:15773-85. [PMID: 21866960 DOI: 10.1021/ja206906d] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The linear tetracyclic TAN-1612 (1) and BMS-192548 (2) were isolated from different filamentous fungal strains and have been examined as potential neuropeptide Y and neurokinin-1 receptor antagonists, respectively. Although the biosynthesis of fungal aromatic polyketides has attracted much interest in recent years, the biosynthetic mechanism for such naphthacenedione-containing products has not been established. Using a targeted genome mining approach, we first located the ada gene cluster responsible for the biosynthesis of 1 in Aspergillus niger ATCC 1015. The connection between 1 and the ada pathway was verified through overexpression of the Zn(2)Cys(6)-type pathway-specific transcriptional regulator AdaR and subsequent gene expression analysis. The enzymes encoded in the ada gene cluster share high sequence similarities to the known apt pathway linked to the biosynthesis of anthraquinone asperthecin 3. Subsequent comparative investigation of these two highly homologous gene clusters by heterologous pathway reconstitution in Saccharomyces cerevisiae revealed a novel α-hydroxylation-dependent Claisen cyclization cascade, which involves a flavin-dependent monooxygenase that hydroxylates the α-carbon of an acyl carrier protein-bound polyketide and a bifunctional metallo-β-lactamase-type thioesterase (MβL-TE). The bifunctional MβL-TE catalyzes the fourth ring cyclization to afford the naphthacenedione scaffold upon α-hydroxylation, whereas it performs hydrolytic release of an anthracenone product in the absence of α-hydroxylation. Through in vitro biochemical characterizations and metal analyses, we verified that the apt MβL-TE is a dimanganese enzyme and requires both Mn(2+) cations for the observed activities. The MβL-TE is the first example of a thioesterase in polyketide biosynthesis that catalyzes the Claisen-like condensation without an α/β hydrolase fold and forms no covalent bond with the substrate. These mechanistic features should be general to the biosynthesis of tetracyclic naphthacenedione compounds in fungi.
Collapse
Affiliation(s)
- Yanran Li
- Department of Chemical and Biomolecular Engineering, University of California Los Angeles, 420 Westwood Plaza, Los Angeles, California 90095, United States
| | | | | | | | | |
Collapse
|
29
|
Solution structures of the acyl carrier protein domain from the highly reducing type I iterative polyketide synthase CalE8. PLoS One 2011; 6:e20549. [PMID: 21674045 PMCID: PMC3107222 DOI: 10.1371/journal.pone.0020549] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 05/03/2011] [Indexed: 12/02/2022] Open
Abstract
Biosynthesis of the enediyne natural product calicheamicins γ1I in Micromonospora echinospora ssp. calichensis is initiated by the iterative polyketide synthase (PKS) CalE8. Recent studies showed that CalE8 produces highly conjugated polyenes as potential biosynthetic intermediates and thus belongs to a family of highly-reducing (HR) type I iterative PKSs. We have determined the NMR structure of the ACP domain (meACP) of CalE8, which represents the first structure of a HR type I iterative PKS ACP domain. Featured by a distinct hydrophobic patch and a glutamate-residue rich acidic patch, meACP adopts a twisted three-helix bundle structure rather than the canonical four-helix bundle structure. The so-called ‘recognition helix’ (α2) of meACP is less negatively charged than the typical type II ACPs. Although loop-2 exhibits greater conformational mobility than other regions of the protein with a missing short helix that can be observed in most ACPs, two bulky non-polar residues (Met992, Phe996) from loop-2 packed against the hydrophobic protein core seem to restrict large movement of the loop and impede the opening of the hydrophobic pocket for sequestering the acyl chains. NMR studies of the hydroxybutyryl- and octanoyl-meACP confirm that meACP is unable to sequester the hydrophobic chains in a well-defined central cavity. Instead, meACP seems to interact with the octanoyl tail through a distinct hydrophobic patch without involving large conformational change of loop-2. NMR titration study of the interaction between meACP and the cognate thioesterase partner CalE7 further suggests that their interaction is likely through the binding of CalE7 to the meACP-tethered polyene moiety rather than direct specific protein-protein interaction.
Collapse
|
30
|
Abstract
Fungal aromatic polyketides constitute a large family of bioactive natural products and are synthesized by the non-reducing group of iterative polyketide synthases (PKSs). Their diverse structures arise from selective enzymatic modifications of reactive, enzyme-bound poly-β-keto intermediates. How iterative PKSs control starter unit selection, polyketide chain initiation and elongation, intermediate folding and cyclization, selective redox or modification reactions during assembly, and product release are central mechanistic questions underlying iterative catalysis. This Review highlights recent insights into these questions, with a particular focus on the biosynthetic programming of fungal aromatic polyketides, and draws comparisons with the allied biosynthetic processes in bacteria.
Collapse
|
31
|
Abstract
FA (fatty acid) synthesis represents a central, conserved process by which acyl chains are produced for utilization in a number of end-products such as biological membranes. Central to FA synthesis, the ACP (acyl carrier protein) represents the cofactor protein that covalently binds all fatty acyl intermediates via a phosphopantetheine linker during the synthesis process. FASs (FA synthases) can be divided into two classes, type I and II, which are primarily present in eukaryotes and bacteria/plants respectively. They are characterized by being composed of either large multifunctional polypeptides in the case of type I or consisting of discretely expressed mono-functional proteins in the type II system. Owing to this difference in architecture, the FAS system has been thought to be a good target for the discovery of novel antibacterial agents, as exemplified by the antituberculosis drug isoniazid. There have been considerable advances in this field in recent years, including the first high-resolution structural insights into the type I mega-synthases and their dynamic behaviour. Furthermore, the structural and dynamic properties of an increasing number of acyl-ACPs have been described, leading to an improved comprehension of this central carrier protein. In the present review we discuss the state of the understanding of FA synthesis with a focus on ACP. In particular, developments made over the past few years are highlighted.
Collapse
|
32
|
Tran L, Broadhurst RW, Tosin M, Cavalli A, Weissman KJ. Insights into Protein-Protein and Enzyme-Substrate Interactions in Modular Polyketide Synthases. ACTA ACUST UNITED AC 2010; 17:705-16. [DOI: 10.1016/j.chembiol.2010.05.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/26/2010] [Accepted: 05/03/2010] [Indexed: 11/29/2022]
|
33
|
Li Y, Image II, Xu W, Image I, Tang Y, Image I. Classification, prediction, and verification of the regioselectivity of fungal polyketide synthase product template domains. J Biol Chem 2010; 285:22764-73. [PMID: 20479000 DOI: 10.1074/jbc.m110.128504] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The fungal iterative nonreducing polyketide synthases (NRPKSs) synthesize aromatic polyketides, many of which have important biological activities. The product template domains (PT) embedded in the multidomain NRPKSs mediate the regioselective cyclization of the highly reactive polyketide backbones and dictate the final structures of the products. Understanding the sequence-activity relationships of different PT domains is therefore an important step toward the prediction of polyketide structures from NRPKS sequences and can enable the genome mining of hundreds of cryptic NRPKSs uncovered via genome sequencing. In this work, we first performed phylogenetic analysis of PT domains from NRPKSs of known functions and showed that the PT domains can be classified into five groups, with each group corresponding to a unique product size or cyclization regioselectivity. Group V contains the formerly unverified PT domains that were identified as C6-C11 aldol cyclases. The regioselectivity of PTs from this group were verified by product-based assays using the PT domain excised from the asperthecin AptA NRPKS. When combined with dissociated PKS4 minimal PKS, or replaced the endogenous PKS4 C2-C7 PT domain in a hybrid NRPKS, AptA-PT directed the C6-C11 cyclization of the nonaketide backbone to yield a tetracyclic pyranoanthraquinone 4. Extensive NMR analysis verified that the backbone of 4 was indeed cyclized with the expected regioselectivity. The PT phylogenetic analysis was then expanded to include approximately 100 PT sequences from unverified NRPKSs. Using the assays developed for AptA-PT, the regioselectivities of additional PT domains were investigated and matched to those predicted by the phylogenetic classifications.
Collapse
Affiliation(s)
- Yanran Li
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, USA
| | | | | | | | | | | |
Collapse
|