51
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Homologous ligands accommodated by discrete conformations of a buried cavity. Proc Natl Acad Sci U S A 2015; 112:5039-44. [PMID: 25847998 DOI: 10.1073/pnas.1500806112] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Conformational change in protein-ligand complexes is widely modeled, but the protein accommodation expected on binding a congeneric series of ligands has received less attention. Given their use in medicinal chemistry, there are surprisingly few substantial series of congeneric ligand complexes in the Protein Data Bank (PDB). Here we determine the structures of eight alkyl benzenes, in single-methylene increases from benzene to n-hexylbenzene, bound to an enclosed cavity in T4 lysozyme. The volume of the apo cavity suffices to accommodate benzene but, even with toluene, larger cavity conformations become observable in the electron density, and over the series two other major conformations are observed. These involve discrete changes in main-chain conformation, expanding the site; few continuous changes in the site are observed. In most structures, two discrete protein conformations are observed simultaneously, and energetic considerations suggest that these conformations are low in energy relative to the ground state. An analysis of 121 lysozyme cavity structures in the PDB finds that these three conformations dominate the previously determined structures, largely modeled in a single conformation. An investigation of the few congeneric series in the PDB suggests that discrete changes are common adaptations to a series of growing ligands. The discrete, but relatively few, conformational states observed here, and their energetic accessibility, may have implications for anticipating protein conformational change in ligand design.
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52
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An S188V mutation alters substrate specificity of non-stereospecific α-haloalkanoic acid dehalogenase E (DehE). PLoS One 2015; 10:e0121687. [PMID: 25816329 PMCID: PMC4376737 DOI: 10.1371/journal.pone.0121687] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 02/03/2015] [Indexed: 11/19/2022] Open
Abstract
The non-stereospecific α-haloalkanoic acid dehalogenase E (DehE) degrades many halogenated compounds but is ineffective against β-halogenated compounds such as 3-chloropropionic acid (3CP). Using molecular dynamics (MD) simulations and site-directed mutagenesis we show here that introducing the mutation S188V into DehE improves substrate specificity towards 3CP. MD simulations showed that residues W34, F37, and S188 of DehE were crucial for substrate binding. DehE showed strong binding ability for D-2-chloropropionic acid (D-2CP) and L-2-chloropropionic acid (L-2CP) but less affinity for 3CP. This reduced affinity was attributed to weak hydrogen bonding between 3CP and residue S188, as the carboxylate of 3CP forms rapidly interconverting hydrogen bonds with the backbone amide and side chain hydroxyl group of S188. By replacing S188 with a valine residue, we reduced the inter-molecular distance and stabilised bonding of the carboxylate of 3CP to hydrogens of the substrate-binding residues. Therefore, the S188V can act on 3CP, although its affinity is less strong than for D-2CP and L-2CP as assessed by Km. This successful alteration of DehE substrate specificity may promote the application of protein engineering strategies to other dehalogenases, thereby generating valuable tools for future bioremediation technologies.
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53
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Chen CC, Cheng KJ, Ko TP, Guo RT. Current Progresses in Phytase Research: Three-Dimensional Structure and Protein Engineering. CHEMBIOENG REVIEWS 2015. [DOI: 10.1002/cben.201400026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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54
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Goyal B, Patel K, Srivastava KR, Durani S. De novo design of stereochemically-bent sixteen-residue β-hairpin as a hydrolase mimic. RSC Adv 2015. [DOI: 10.1039/c5ra19015k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Stepwise design of sixteen-residue β-hairpin as a hydrolase mimic involving fold design by stereochemical mutation followed by inverse-design of sequence.
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Affiliation(s)
- Bhupesh Goyal
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai–400076
- India
| | - Kirti Patel
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai–400076
- India
| | | | - Susheel Durani
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai–400076
- India
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55
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Sudi IY, Hamid AAA, Shamsir MS, Jamaluddin H, Wahab RA, Huyop F. Insights into the stereospecificity of the d-specific dehalogenase from Rhizobium sp. RC1 toward d- and l-2-chloropropionate. BIOTECHNOL BIOTEC EQ 2014; 28:608-615. [PMID: 26740767 PMCID: PMC4684057 DOI: 10.1080/13102818.2014.937907] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 06/06/2014] [Indexed: 11/15/2022] Open
Abstract
Halogenated compounds are recalcitrant environmental pollutants prevalent in agricultural fields, waste waters and industrial by-products, but they can be degraded by dehalogenase-containing microbes. Notably, 2-haloalkanoic acid dehalogenases are employed to resolve optically active chloropropionates, as exemplified by the d-specific dehalogenase from Rhizobium sp. RCI (DehD), which acts on d-2-chloropropionate but not on its l-enantiomer. The catalytic residues of this dehalogenase responsible for its affinity toward d-2-chloropropionate have not been experimentally determined, although its three-dimensional crystal structure has been solved. For this study, we performed in silico docking and molecular dynamic simulations of complexes formed by this dehalogenase and d- or l-2-chloropropionate. Arg134 of the enzyme plays the key role in the stereospecific binding and Arg16 is in a position that would allow it to activate a water molecule for hydrolytic attack on the d-2-chloropropionate chiral carbon for release of the halide ion to yield l-2-hydroxypropionate. We propose that within the DehD active site, the NH group of Arg134 can form a hydrogen bond with the carboxylate of d-2-chloropropionate with a strength of ∼4 kcal/mol that may act as an acid–base catalyst, whereas, when l-2-chloropropionate is present, this bond cannot be formed. The significance of the present work is vital for rational design of this dehalogenase in order to confirm the involvement of Arg16 and Arg134 residues implicated in hydrolysis and binding of d-2-chloropropionate in the active site of d-specific dehalogenase from Rhizobium sp. RC1.
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Affiliation(s)
- Ismaila Yada Sudi
- Faculty of Biosciences and Medical Engineering (FBME), Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
| | | | - Mohd Shahir Shamsir
- Faculty of Biosciences and Medical Engineering (FBME), Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
| | - Haryati Jamaluddin
- Faculty of Biosciences and Medical Engineering (FBME), Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
| | | | - Fahrul Huyop
- Faculty of Biosciences and Medical Engineering (FBME), Universiti Teknologi Malaysia , Johor Bahru , Johor , Malaysia
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56
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de Diego I, Veillard F, Sztukowska MN, Guevara T, Potempa B, Pomowski A, Huntington JA, Potempa J, Gomis-Rüth FX. Structure and mechanism of cysteine peptidase gingipain K (Kgp), a major virulence factor of Porphyromonas gingivalis in periodontitis. J Biol Chem 2014; 289:32291-32302. [PMID: 25266723 DOI: 10.1074/jbc.m114.602052] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cysteine peptidases are key proteolytic virulence factors of the periodontopathogen Porphyromonas gingivalis, which causes chronic periodontitis, the most prevalent dysbiosis-driven disease in humans. Two peptidases, gingipain K (Kgp) and R (RgpA and RgpB), which differ in their selectivity after lysines and arginines, respectively, collectively account for 85% of the extracellular proteolytic activity of P. gingivalis at the site of infection. Therefore, they are promising targets for the design of specific inhibitors. Although the structure of the catalytic domain of RgpB is known, little is known about Kgp, which shares only 27% sequence identity. We report the high resolution crystal structure of a competent fragment of Kgp encompassing the catalytic cysteine peptidase domain and a downstream immunoglobulin superfamily-like domain, which is required for folding and secretion of Kgp in vivo. The structure, which strikingly resembles a tooth, was serendipitously trapped with a fragment of a covalent inhibitor targeting the catalytic cysteine. This provided accurate insight into the active site and suggested that catalysis may require a catalytic triad, Cys(477)-His(444)-Asp(388), rather than the cysteine-histidine dyad normally found in cysteine peptidases. In addition, a 20-Å-long solvent-filled interior channel traverses the molecule and links the bottom of the specificity pocket with the molecular surface opposite the active site cleft. This channel, absent in RgpB, may enhance the plasticity of the enzyme, which would explain the much lower activity in vitro toward comparable specific synthetic substrates. Overall, the present results report the architecture and molecular determinants of the working mechanism of Kgp, including interaction with its substrates.
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Affiliation(s)
- Iñaki de Diego
- Proteolysis Lab, Molecular Biology Institute of Barcelona, Spanish Research Council (Consejo Superior de Investigaciones Cientificas), Barcelona Science Park, Helix Building, Baldiri Reixac 15-21, 08028 Barcelona, Catalonia, Spain
| | - Florian Veillard
- Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, Kentucky 40202
| | - Maryta N Sztukowska
- Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, Kentucky 40202
| | - Tibisay Guevara
- Proteolysis Lab, Molecular Biology Institute of Barcelona, Spanish Research Council (Consejo Superior de Investigaciones Cientificas), Barcelona Science Park, Helix Building, Baldiri Reixac 15-21, 08028 Barcelona, Catalonia, Spain
| | - Barbara Potempa
- Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, Kentucky 40202
| | - Anja Pomowski
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - James A Huntington
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Jan Potempa
- Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, Kentucky 40202,; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland, and.
| | - F Xavier Gomis-Rüth
- Proteolysis Lab, Molecular Biology Institute of Barcelona, Spanish Research Council (Consejo Superior de Investigaciones Cientificas), Barcelona Science Park, Helix Building, Baldiri Reixac 15-21, 08028 Barcelona, Catalonia, Spain,.
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57
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Affiliation(s)
- Bettina M. Nestl
- Institute
of Technical Biochemistry, University of Stuttgart, Allmandring
31, 70569 Stuttgart, Germany
| | - Bernhard Hauer
- Institute
of Technical Biochemistry, University of Stuttgart, Allmandring
31, 70569 Stuttgart, Germany
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58
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Selwa E, Huynh T, Ciccotti G, Maragliano L, Malliavin TE. Temperature-accelerated molecular dynamics gives insights into globular conformations sampled in the free state of the AC catalytic domain. Proteins 2014; 82:2483-96. [PMID: 24863163 DOI: 10.1002/prot.24612] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 05/05/2014] [Accepted: 05/13/2014] [Indexed: 01/16/2023]
Abstract
The catalytic domain of the adenyl cyclase (AC) toxin from Bordetella pertussis is activated by interaction with calmodulin (CaM), resulting in cAMP overproduction in the infected cell. In the X-ray crystallographic structure of the complex between AC and the C terminal lobe of CaM, the toxin displays a markedly elongated shape. As for the structure of the isolated protein, experimental results support the hypothesis that more globular conformations are sampled, but information at atomic resolution is still lacking. Here, we use temperature-accelerated molecular dynamics (TAMD) simulations to generate putative all-atom models of globular conformations sampled by CaM-free AC. As collective variables, we use centers of mass coordinates of groups of residues selected from the analysis of standard molecular dynamics (MD) simulations. Results show that TAMD allows extended conformational sampling and generates AC conformations that are more globular than in the complexed state. These structures are then refined via energy minimization and further unrestrained MD simulations to optimize inter-domain packing interactions, thus resulting in the identification of a set of hydrogen bonds present in the globular conformations.
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Affiliation(s)
- Edithe Selwa
- Institut Pasteur and CNRS UMR 3528, rue du Dr Roux, Unité de Bioinformatique Structurale, 75015, Paris, France; Université Pierre et Marie Curie, Cellule Pasteur UPMC, rue du Dr Roux, 75015, Paris, France
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59
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Structural and functional analysis of a novel psychrophilic β-mannanase from Glaciozyma antarctica PI12. J Comput Aided Mol Des 2014; 28:685-98. [PMID: 24849507 DOI: 10.1007/s10822-014-9751-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/12/2014] [Indexed: 12/29/2022]
Abstract
The structure of a novel psychrophilic β-mannanase enzyme from Glaciozyma antarctica PI12 yeast has been modelled and analysed in detail. To our knowledge, this is the first attempt to model a psychrophilic β-mannanase from yeast. To this end, a 3D structure of the enzyme was first predicted using a threading method because of the low sequence identity (<30%) using MODELLER9v12 and simulated using GROMACS at varying low temperatures for structure refinement. Comparisons with mesophilic and thermophilic mannanases revealed that the psychrophilic mannanase contains longer loops and shorter helices, increases in the number of aromatic and hydrophobic residues, reductions in the number of hydrogen bonds and salt bridges and numerous amino acid substitutions on the surface that increased the flexibility and its efficiency for catalytic reactions at low temperatures.
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60
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Prabhakar PK, Rao KK, Balaji PV. The Cys78–Asn88 loop region of the Campylobacter jejuni CstII is essential for α2,3-sialyltransferase activity: analysis of the His85 mutants. ACTA ACUST UNITED AC 2014; 156:229-38. [DOI: 10.1093/jb/mvu033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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61
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Alvarez L, Espaillat A, Hermoso JA, de Pedro MA, Cava F. Peptidoglycan remodeling by the coordinated action of multispecific enzymes. Microb Drug Resist 2014; 20:190-8. [PMID: 24799190 DOI: 10.1089/mdr.2014.0047] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The peptidoglycan (PG) cell wall constitutes the main defense barrier of bacteria against environmental insults and acts as communication interface. The biochemistry of this macromolecule has been well characterized throughout the years but recent discoveries have unveiled its chemical plasticity under environmental stresses. Non-canonical D-amino acids (NCDAA) are produced and released to the extracellular media by diverse bacteria. Such molecules govern cell wall adaptation to challenging environments through their incorporation into the polymer, a widespread capability among bacteria that reveals the inherent catalytic plasticity of the enzymes involved in the cell wall metabolism. Here, we analyze the recent structural and biochemical characterization of Bsr, a new family of broad spectrum racemases able to generate a wide range of NCDAA. We also discuss the necessity of a coordinated action of PG multispecific enzymes to generate adequate levels of modification in the murein sacculus. Finally, we also highlight how this catalytic plasticity of NCDAA-incorporating enzymes has allowed the development of new revolutionary methodologies for the study of PG modes of growth and in vivo dynamics.
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Affiliation(s)
- Laura Alvarez
- 1 Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University , Umeå, Sweden
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62
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Conformational landscapes for KMSKS loop in tyrosyl-tRNA synthetases. ACTA ACUST UNITED AC 2014; 15:45-61. [DOI: 10.1007/s10969-014-9178-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 03/08/2014] [Indexed: 01/20/2023]
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63
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Kumar V, Yedavalli P, Gupta V, Rao NM. Engineering lipase A from mesophilic Bacillus subtilis for activity at low temperatures. Protein Eng Des Sel 2014; 27:73-82. [PMID: 24402332 DOI: 10.1093/protein/gzt064] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Loops or unordered regions of a protein are structurally dynamic and are strongly implicated in activity, stability and proteolytic susceptibility of proteins. Diminished activity of proteins at lower temperatures is considered to be due to compromised dynamics of the protein at lower temperatures. To evolve an active mesophilic lipase (Bacillus subtilis) at low temperatures, we subjected all the loop residues (n = 88) to site saturation mutagenesis (SSM). Based on a three-level screening protocol, we identified 14 substitutions, among 16,000 mutant population, which contributed to a substantial increase in activity at 5 °C. Based on the preliminary activity of recombinants at several temperatures, 5 substitutions among the 14 were found to be beneficial. A recombinant of these five mutations, named as 5CR, exhibited 7-fold higher catalytic efficiency than wild-type (WT) lipase at 10 °C. All the mutants, individually and in a recombinant (5CR), were characterized by substrate-binding parameters, melting temperatures and secondary structure. 5CR was similar to WT in substrate preferences and showed a significant improvement in activity at both lower and higher temperatures compared with the WT. To establish the contribution of mutations on the dynamics of the protein, we performed 100-ns molecular dynamics (MD) simulations on the WT and mutant lipase at 10 and 37 °C. The root mean square fluctuations (RMSFs) indeed showed that the mutations enhance the protein dynamics locally in the loop region having a catalytic residue, which may help in improved activities at lower temperatures.
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Affiliation(s)
- Virender Kumar
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500007, India
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64
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Abstract
Catalysts often perform miraculous transformations of reactants A to very different products P in seemingly a single step. Such catalysts appear as a black box. This tutorial shows how we can shine light into this black box and understand the reaction mechanism. In particular, it aims at explaining some of the fundamental principles of the action of a catalyst.
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Affiliation(s)
- Emil Roduner
- Institute of Physical Chemistry
- University of Stuttgart
- D-70569 Stuttgart, Germany
- Chemistry Department
- University of Pretoria
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65
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Wang J, Shao Q, Xu Z, Liu Y, Yang Z, Cossins BP, Jiang H, Chen K, Shi J, Zhu W. Exploring transition pathway and free-energy profile of large-scale protein conformational change by combining normal mode analysis and umbrella sampling molecular dynamics. J Phys Chem B 2013; 118:134-43. [PMID: 24350625 DOI: 10.1021/jp4105129] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Large-scale conformational changes of proteins are usually associated with the binding of ligands. Because the conformational changes are often related to the biological functions of proteins, understanding the molecular mechanisms of these motions and the effects of ligand binding becomes very necessary. In the present study, we use the combination of normal-mode analysis and umbrella sampling molecular dynamics simulation to delineate the atomically detailed conformational transition pathways and the associated free-energy landscapes for three well-known protein systems, viz., adenylate kinase (AdK), calmodulin (CaM), and p38α kinase in the absence and presence of respective ligands. For each protein under study, the transient conformations along the conformational transition pathway and thermodynamic observables are in agreement with experimentally and computationally determined ones. The calculated free-energy profiles reveal that AdK and CaM are intrinsically flexible in structures without obvious energy barrier, and their ligand binding shifts the equilibrium from the ligand-free to ligand-bound conformation (population shift mechanism). In contrast, the ligand binding to p38α leads to a large change in free-energy barrier (ΔΔG ≈ 7 kcal/mol), promoting the transition from DFG-in to DFG-out conformation (induced fit mechanism). Moreover, the effect of the protonation of D168 on the conformational change of p38α is also studied, which reduces the free-energy difference between the two functional states of p38α and thus further facilitates the conformational interconversion. Therefore, the present study suggests that the detailed mechanism of ligand binding and the associated conformational transition is not uniform for all kinds of proteins but correlated to their respective biological functions.
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Affiliation(s)
- Jinan Wang
- Drug Discovery and Design Center, CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , 555 Zuchongzhi Road, Shanghai, 201203, China
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66
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Lukina MV, Popov AV, Koval VV, Vorobjev YN, Fedorova OS, Zharkov DO. DNA damage processing by human 8-oxoguanine-DNA glycosylase mutants with the occluded active site. J Biol Chem 2013; 288:28936-47. [PMID: 23955443 DOI: 10.1074/jbc.m113.487322] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
8-Oxoguanine-DNA glycosylase (OGG1) removes premutagenic lesion 8-oxoguanine (8-oxo-G) from DNA and then nicks the nascent abasic (apurinic/apyrimidinic) site by β-elimination. Although the structure of OGG1 bound to damaged DNA is known, the dynamic aspects of 8-oxo-G recognition are not well understood. To comprehend the mechanisms of substrate recognition and processing, we have constructed OGG1 mutants with the active site occluded by replacement of Cys-253, which forms a wall of the base-binding pocket, with bulky leucine or isoleucine. The conformational dynamics of OGG1 mutants were characterized by single-turnover kinetics and stopped-flow kinetics with fluorescent detection. Additionally, the conformational mobility of wild type and the mutant OGG1 substrate complex was assessed using molecular dynamics simulations. Although pocket occlusion distorted the active site and greatly decreased the catalytic activity of OGG1, it did not fully prevent processing of 8-oxo-G and apurinic/apyrimidinic sites. Both mutants were notably stimulated in the presence of free 8-bromoguanine, indicating that this base can bind to the distorted OGG1 and facilitate β-elimination. The results agree with the concept of enzyme plasticity, suggesting that the active site of OGG1 is flexible enough to compensate partially for distortions caused by mutation.
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Affiliation(s)
- Maria V Lukina
- From the Siberian Branch of the Russian Academy of Sciences Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Avenue, Novosibirsk 630090 and
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67
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Stefl S, Nishi H, Petukh M, Panchenko AR, Alexov E. Molecular mechanisms of disease-causing missense mutations. J Mol Biol 2013; 425:3919-36. [PMID: 23871686 DOI: 10.1016/j.jmb.2013.07.014] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 07/04/2013] [Accepted: 07/10/2013] [Indexed: 12/23/2022]
Abstract
Genetic variations resulting in a change of amino acid sequence can have a dramatic effect on stability, hydrogen bond network, conformational dynamics, activity and many other physiologically important properties of proteins. The substitutions of only one residue in a protein sequence, so-called missense mutations, can be related to many pathological conditions and may influence susceptibility to disease and drug treatment. The plausible effects of missense mutations range from affecting the macromolecular stability to perturbing macromolecular interactions and cellular localization. Here we review the individual cases and genome-wide studies that illustrate the association between missense mutations and diseases. In addition, we emphasize that the molecular mechanisms of effects of mutations should be revealed in order to understand the disease origin. Finally, we report the current state-of-the-art methodologies that predict the effects of mutations on protein stability, the hydrogen bond network, pH dependence, conformational dynamics and protein function.
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Affiliation(s)
- Shannon Stefl
- Computational Biophysics and Bioinformatics, Department of Physics, Clemson University, Clemson, SC 29634, USA
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68
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Schroeder I, Gazzarrini S, Ferrara G, Thiel G, Hansen UP, Moroni A. Creation of a reactive oxygen species-insensitive Kcv channel. Biochemistry 2013; 52:3130-7. [PMID: 23578303 DOI: 10.1021/bi3016197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The current of the minimal viral K(+) channel Kcv(PCBV-1) heterologously expressed in Xenopus oocytes is strongly inhibited by reactive oxygen species (ROS) like H(2)O(2). Possible targets for the ROS effect are two cysteines (C53 and C79) and four methionines (M1, M15, M23, and M26). The C53A/C79A and M23L/M26L double mutations maintained the same ROS sensitivity as the wild type. However, M15L as a single mutant or in combination with C53A/C79A and/or M23L/M26L caused a complete loss of sensitivity to H(2)O(2). These results indicate a prominent role of M15 at the cytosolic end of the outer transmembrane helix for gating of Kcv(PCBV-1). Furthermore, even though the channel lacks a canonical voltage sensor, it exhibits a weak voltage sensitivity, resulting in a slight activation in the millisecond range after a voltage step to negative potentials. The M15L mutation inverts this kinetics into an inactivation, underlining the critical role of this residue for gating. The negative slope of the I-V curves of M15L is the same as in the wild type, indicating that the selectivity filter is not involved.
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Affiliation(s)
- Indra Schroeder
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy.
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69
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Fadouloglou VE, Kapanidou M, Agiomirgianaki A, Arnaouteli S, Bouriotis V, Glykos NM, Kokkinidis M. Structure determination through homology modelling and torsion-angle simulated annealing: application to a polysaccharide deacetylase from Bacillus cereus. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:276-83. [PMID: 23385463 DOI: 10.1107/s0907444912045829] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 11/06/2012] [Indexed: 11/10/2022]
Abstract
The structure of BC0361, a polysaccharide deacetylase from Bacillus cereus, has been determined using an unconventional molecular-replacement procedure. Tens of putative models of the C-terminal domain of the protein were constructed using a multitude of homology-modelling algorithms, and these were tested for the presence of signal in molecular-replacement calculations. Of these, only the model calculated by the SAM-T08 server gave a consistent and convincing solution, but the resulting model was too inaccurate to allow phase determination to proceed to completion. The application of slow-cooling torsion-angle simulated annealing (started from a very high temperature) drastically improved this initial model to the point of allowing phasing through cycles of model building and refinement to be initiated. The structure of the protein is presented with emphasis on the presence of a C(α)-modified proline at its active site, which was modelled as an α-hydroxy-L-proline.
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Affiliation(s)
- Vasiliki E Fadouloglou
- Department of Molecular Biology and Genetics, Democritus University of Thrace, University Campus, 68100 Alexandroupolis, Greece
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Meher BR, Patel S. Structural and dynamical aspects of HIV-1 protease and its role in drug resistance. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 92:299-324. [PMID: 23954105 DOI: 10.1016/b978-0-12-411636-8.00008-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Acquired immunodeficiency syndrome (AIDS) caused by the retrovirus human immunodeficiency virus (HIV) has become a major epidemic afflicting mankind. The Joint United Nations Program on HIV/AIDS (UNAIDS) projection shows the existence of millions of AIDS patients at the end of 2012. All the Food and Drug Administration (FDA)-approved drugs are getting ineffective due to resistance offered by the mutation-prone HIV. Hence, there is an urgent need for developing new drugs with greater potential. HIV life cycle is controlled by the activities of its essential proteins like glycoproteins (gp41 and gp120), HIV reverse transcriptase (HIV-RT), HIV integrase (HIV-IN), and HIV-1 protease (HIV-pr). This chapter focuses on the protein HIV-pr, which is important for the cleavage of Gag and Gag-Pol polyproteins to form mature, structural, and functional virions. The conformation and dynamics of the protein HIV-pr play a pivotal role in ligand binding and the catalytic process, which is affected by the rapid point mutations and various physiological parameters. The effect of the mutations and the varied simulation protocols on conformational dynamics and drug resistance of HIV-pr is discussed.
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Affiliation(s)
- Biswa Ranjan Meher
- Department of Chemistry, Gottwald Center for the Sciences, University of Richmond, Richmond, Virginia, USA.
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