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Pan K, Liu Z, Zhang Z, Jin S, Yu Z, Liu T, Zhang T, Zhao J, Li Z. Improving the Specific Activity and Thermostability of Psychrophilic Xylosidase AX543 by Comparative Mutagenesis. Foods 2022; 11:foods11162463. [PMID: 36010463 PMCID: PMC9407119 DOI: 10.3390/foods11162463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/21/2022] [Accepted: 07/28/2022] [Indexed: 11/16/2022] Open
Abstract
Improving the specific activity and thermostability of psychrophilic xylosidase is important for improving its enzymatic performance and promoting its industrial application. Herein, a psychrophilic xylosidase AX543 exhibited activity in the temperature range between 0 and 35 °C, with optimum activity at 20 °C, which is lower than that of other reported psychrophilic xylosidases. The thermostability, specific activity, and catalytic efficiency of the site-directed variants G110S, Q201R, and L2 were significantly enhanced, without affecting the optimal reaction temperature. Comparative protein structural analysis and molecular dynamics simulation indicated that these improvements might be the result of the increased hydrogen bonds interaction and improved structural rigidity. Furthermore, homologous module substitution with four segments demonstrated that the psychrophilic characteristics of AX543 are the results of the whole protein structure, and the C-terminal segment A4 appears to be more essential in determining psychrophilic characteristics, exhibiting potentiality to produce more psychrophilic xylosidases. This study provides valuable structural information on psychrophilic xylosidases and also offers attractive modification strategies to modify catalytic activity, thermostability, and optimal reaction temperature.
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Affiliation(s)
- Kungang Pan
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Zhongqi Liu
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Zhengjie Zhang
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Shanzheng Jin
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Zhao Yu
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Tianhui Liu
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Tongcun Zhang
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Junqi Zhao
- School of Chemical and Biological Engineering, Qilu Institute of Technology, Jinan 250200, China
- Correspondence: (J.Z.); (Z.L.)
| | - Zhongyuan Li
- State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Correspondence: (J.Z.); (Z.L.)
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Qureshi R, Ghosh A, Yan H. Correlated Motions and Dynamics in Different Domains of Epidermal Growth Factor Receptor With L858R and T790M Mutations. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2022; 19:383-394. [PMID: 32750848 DOI: 10.1109/tcbb.2020.2995569] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Non-small cell lung cancer with an activating epidermal growth factor receptor (EGFR) mutation responds well to targeted drugs. In most cases, drug resistance appears after about a year. Several studies have been conducted on the kinase domain of EGFR to understand the drug resistance mechanism. Since EGFR is a multi-domain protein, mutation in the kinase domain may affect the other domains as well. In this study, we examine the complete structure of the multi-domain EGFR protein and its mutants. We performed molecular dynamics simulations for wildtype EGFR, EGFR with L858R mutation, and EGFR with L858R and T790M mutations. We applied normal mode analysis and complex network analysis to extract the correlated motions in the domains of EGFR. The normal modes are used to construct the dynamic cross-correlation map (DCCM). Simulation results show different patterns of correlated motions in each domain of EGFR mutants compared to the wildtype. In Domains 1 and 3 of the extracellular region, a small number of weak positively correlated motions are extracted. Domains 2 and 4 show large numbers of both positive and negative motions. However, the negatively correlated motions are stronger in mutant structures compared to the wildtype. In Domain 7, some residues showed a positive correlation around the main diagonal. We also identified different communities, nodes and crucial residues in the domains of the structures, which can be important for the function of EGFR. Moreover, hydrogen bond analysis is performed for the stability analysis. The mutant structures have fewer hydrogen bonds compared to the wildtype. Overall, these findings are useful for understanding the dynamics and communications in EGFR domains.
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Fang X, Huang J, Zhang R, Wang F, Zhang Q, Li G, Yan J, Zhang H, Yan Y, Xu L. Convolution Neural Network-Based Prediction of Protein Thermostability. J Chem Inf Model 2019; 59:4833-4843. [PMID: 31657922 DOI: 10.1021/acs.jcim.9b00220] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Most natural proteins exhibit poor thermostability, which limits their industrial application. Computer-aided rational design is an efficient purpose-oriented method that can improve protein thermostability. Numerous machine-learning-based methods have been designed to predict the changes in protein thermostability induced by mutations. However, all of these methods have certain limitations due to existing mutation coding methods that overlook protein sequence features. Here we propose a method to predict protein thermostability using convolutional neural networks based on an in-depth study of thermostability-related protein properties. This method comprises a three-dimensional coding algorithm, including protein mutation information and a strategy to extract neighboring features at protein mutation sites based on multiscale convolution. The accuracies on the S1615 and S388 data sets, which are widely used for protein thermostability predictions, reached 86.4 and 87%, respectively. The Matthews correlation coefficient was nearly double those produced using other methods. Furthermore, a model was constructed to predict the thermostability of Rhizomucor miehei lipase mutants based on the S3661 data set, a single amino acid mutation data set screened from the ProTherm protein thermodynamics database. Compared with the RIF strategy, which consists of three algorithms, i.e., Rosetta ddg monomer, I Mutant 3.0, and FoldX, the accuracy of the proposed method was higher (75.0 vs 66.7%), and the negative sample resolution was simultaneously enhanced. These results indicate that our prediction method more effectively assessed the protein thermostability and distinguished its features, making it a powerful tool to devise mutations that enhance the thermostability of proteins, particularly enzymes.
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Affiliation(s)
- Xingrong Fang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Jinsha Huang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Rui Zhang
- Editorial Board of the Journal of Wuhan Institute of Technology , Wuhan Institute of Technology , Wuhan 430074 , P. R. China
| | - Fei Wang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Qiuyu Zhang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Guanlin Li
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Jinyong Yan
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Houjin Zhang
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Yunjun Yan
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
| | - Li Xu
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , P. R. China
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4
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Goyal VD, Sullivan BJ, Magliery TJ. Phylogenetic spread of sequence data affects fitness of consensus enzymes: Insights from triosephosphate isomerase. Proteins 2019; 88:274-283. [PMID: 31407418 DOI: 10.1002/prot.25799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 07/26/2019] [Accepted: 08/08/2019] [Indexed: 11/08/2022]
Abstract
The concept of consensus in multiple sequence alignments (MSAs) has been used to design and engineer proteins previously with some success. However, consensus design implicitly assumes that all amino acid positions function independently, whereas in reality, the amino acids in a protein interact with each other and work cooperatively to produce the optimum structure required for its function. Correlation analysis is a tool that can capture the effect of such interactions. In a previously published study, we made consensus variants of the triosephosphate isomerase (TIM) protein using MSAs that included sequences form both prokaryotic and eukaryotic organisms. These variants were not completely native-like and were also surprisingly different from each other in terms of oligomeric state, structural dynamics, and activity. Extensive correlation analysis of the TIM database has revealed some clues about factors leading to the unusual behavior of the previously constructed consensus proteins. Among other things, we have found that the more ill-behaved consensus mutant had more broken correlations than the better-behaved consensus variant. Moreover, we report three correlation and phylogeny-based consensus variants of TIM. These variants were more native-like than the previous consensus mutants and considerably more stable than a wild-type TIM from a mesophilic organism. This study highlights the importance of choosing the appropriate diversity of MSA for consensus analysis and provides information that can be used to engineer stable enzymes.
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Affiliation(s)
- Venuka Durani Goyal
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio
| | - Brandon J Sullivan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio.,Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio
| | - Thomas J Magliery
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio
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5
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Phylogenetic, molecular evolution and structural analyses of the WFDC1/prostate stromal protein 20 (ps20). Gene 2019; 686:125-140. [DOI: 10.1016/j.gene.2018.10.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/07/2018] [Accepted: 10/19/2018] [Indexed: 12/20/2022]
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6
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Zhao Y, Wang Y, Gao Y, Li G, Huang J. Integrated analysis of residue coevolution and protein structures capture key protein sectors in HIV-1 proteins. PLoS One 2015; 10:e0117506. [PMID: 25671429 PMCID: PMC4324911 DOI: 10.1371/journal.pone.0117506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 12/24/2014] [Indexed: 02/07/2023] Open
Abstract
HIV type 1 (HIV-1) is characterized by its rapid genetic evolution, leading to challenges in anti-HIV therapy. However, the sequence variations in HIV-1 proteins are not randomly distributed due to a combination of functional constraints and genetic drift. In this study, we examined patterns of sequence variability for evidence of linked sequence changes (termed as coevolution or covariation) in 15 HIV-1 proteins. It shows that the percentage of charged residues in the coevolving residues is significantly higher than that in all the HIV-1 proteins. Most of the coevolving residues are spatially proximal in the protein structures and tend to form relatively compact and independent units in the tertiary structures, termed as "protein sectors". These protein sectors are closely associated with anti-HIV drug resistance, T cell epitopes, and antibody binding sites. Finally, we explored candidate peptide inhibitors based on the protein sectors. Our results can establish an association between the coevolving residues and molecular functions of HIV-1 proteins, and then provide us with valuable knowledge of pathology of HIV-1 and therapeutics development.
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Affiliation(s)
- Yuqi Zhao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, No.32 Jiaochang Donglu Kunming, 650223 Yunnan, China
- Department of Integrative Biology and Physiology, University of California, Los Angeles, 610 Charles E. Young Drive East, Los Angeles, California, United States of America
- * E-mail: (YZ); (JH)
| | - Yanjie Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Yuedong Gao
- Kunming Biological Diversity Regional Center of Instruments, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Gonghua Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, No.32 Jiaochang Donglu Kunming, 650223 Yunnan, China
| | - Jingfei Huang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, No.32 Jiaochang Donglu Kunming, 650223 Yunnan, China
- Collaborative Innovation Center for Natural Products and Biological Drugs of Yunnan, Kunming, Yunnan 650223, China
- * E-mail: (YZ); (JH)
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Nelson SK, Kelleher A, Robinson G, Reiling S, Asojo OA. Structure of 2-keto-3-deoxy-D-manno-octulosonate-8-phosphate synthase from Pseudomonas aeruginosa. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1084-8. [PMID: 24100553 PMCID: PMC3792661 DOI: 10.1107/s1744309113023993] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 08/27/2013] [Indexed: 11/10/2022]
Abstract
Pseudomonas aeruginosa is a major cause of opportunistic infection and is resistant to most antibiotics. As part of efforts to generate much-needed new antibiotics, structural studies of enzymes that are critical for the virulence of P. aeruginosa but are absent in mammals have been initiated. 2-Keto-3-deoxy-D-manno-octulosonate-8-phosphate synthase (KDO8Ps), also known as 2-dehydro-3-deoxyphosphooctonate aldolase, is vital for the survival and virulence of P. aeruginosa. This enzyme catalyzes a key step in the synthesis of the lipopolysaccharide (LPS) of most Gram-negative bacteria: the condensation reaction between phosphoenolpyruvate (PEP) and arabinose 5-phosphate to produce 2-keto-3-deoxy-D-manno-octulosonate-8-phosphate (KDO8P). This step is vital for the proper synthesis and assembly of LPS and the survival of P. aeruginosa. Here, the recombinant expression, purification and crystal structure of KDO8Ps from P. aeruginosa are presented. Orthorhombic crystals were obtained by vapor diffusion in sitting drops in the presence of 1 mM phosphoenlpyruvate. The structure reveals the prototypical α/β TIM-barrel structure expected from this family of enzymes and contains a tetramer in the asymmetric unit.
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Affiliation(s)
- Sarah K. Nelson
- National School of Tropical Medicine, Baylor College of Medicine, 1102 Bates Avenue, Houston, TX 77030, USA
| | - Alan Kelleher
- National School of Tropical Medicine, Baylor College of Medicine, 1102 Bates Avenue, Houston, TX 77030, USA
| | - Gonteria Robinson
- National School of Tropical Medicine, Baylor College of Medicine, 1102 Bates Avenue, Houston, TX 77030, USA
| | - Scott Reiling
- National School of Tropical Medicine, Baylor College of Medicine, 1102 Bates Avenue, Houston, TX 77030, USA
| | - Oluwatoyin A. Asojo
- National School of Tropical Medicine, Baylor College of Medicine, 1102 Bates Avenue, Houston, TX 77030, USA
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8
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Residue mutations and their impact on protein structure and function: detecting beneficial and pathogenic changes. Biochem J 2013; 449:581-94. [DOI: 10.1042/bj20121221] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The present review focuses on the evolution of proteins and the impact of amino acid mutations on function from a structural perspective. Proteins evolve under the law of natural selection and undergo alternating periods of conservative evolution and of relatively rapid change. The likelihood of mutations being fixed in the genome depends on various factors, such as the fitness of the phenotype or the position of the residues in the three-dimensional structure. For example, co-evolution of residues located close together in three-dimensional space can occur to preserve global stability. Whereas point mutations can fine-tune the protein function, residue insertions and deletions (‘decorations’ at the structural level) can sometimes modify functional sites and protein interactions more dramatically. We discuss recent developments and tools to identify such episodic mutations, and examine their applications in medical research. Such tools have been tested on simulated data and applied to real data such as viruses or animal sequences. Traditionally, there has been little if any cross-talk between the fields of protein biophysics, protein structure–function and molecular evolution. However, the last several years have seen some exciting developments in combining these approaches to obtain an in-depth understanding of how proteins evolve. For example, a better understanding of how structural constraints affect protein evolution will greatly help us to optimize our models of sequence evolution. The present review explores this new synthesis of perspectives.
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9
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Durani V, Magliery TJ. Protein engineering and stabilization from sequence statistics: variation and covariation analysis. Methods Enzymol 2013; 523:237-56. [PMID: 23422433 DOI: 10.1016/b978-0-12-394292-0.00011-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The concepts of consensus and correlation in multiple sequence alignments (MSAs) have been used in the past to understand and engineer proteins. However, there are multiple ways of acquiring MSA databases and also numerous mathematical metrics that can be applied to calculate each of the parameters. This chapter describes an overall methodology that we have chosen to employ for acquiring and statistically analyzing MSAs. We have provided a step-by-step protocol for calculating relative entropy and mutual information metrics and describe how they can be used to predict mutations that have a high probability of stabilizing a protein. This protocol allows for flexibility for modification of formulae and parameters without using anything more complicated than Microsoft Excel. We have also demonstrated various aspects of data analysis by carrying out a sample analysis on the BPTI-Kunitz family of proteins and identified mutations that would be predicted to stabilize this protein based on consensus and correlation values.
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Affiliation(s)
- Venuka Durani
- Department of Chemistry, The Ohio State University, Columbus, Ohio, USA
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Li X, Zhang Z, Song J. Computational enzyme design approaches with significant biological outcomes: progress and challenges. Comput Struct Biotechnol J 2012; 2:e201209007. [PMID: 24688648 PMCID: PMC3962085 DOI: 10.5936/csbj.201209007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/27/2012] [Accepted: 10/04/2012] [Indexed: 11/29/2022] Open
Abstract
Enzymes are powerful biocatalysts, however, so far there is still a large gap between the number of enzyme-based practical applications and that of naturally occurring enzymes. Multiple experimental approaches have been applied to generate nearly all possible mutations of target enzymes, allowing the identification of desirable variants with improved properties to meet the practical needs. Meanwhile, an increasing number of computational methods have been developed to assist in the modification of enzymes during the past few decades. With the development of bioinformatic algorithms, computational approaches are now able to provide more precise guidance for enzyme engineering and make it more efficient and less laborious. In this review, we summarize the recent advances of method development with significant biological outcomes to provide important insights into successful computational protein designs. We also discuss the limitations and challenges of existing methods and the future directions that should improve them.
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Affiliation(s)
- Xiaoman Li
- National Engineering Laboratory for Industrial Enzymes and Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, Tianjin 300308, China
| | - Ziding Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jiangning Song
- National Engineering Laboratory for Industrial Enzymes and Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, Tianjin 300308, China ; Department of Biochemistry and Molecular Biology and ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Melbourne, VIC 3800, Australia
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Pasi M, Tiberti M, Arrigoni A, Papaleo E. xPyder: a PyMOL plugin to analyze coupled residues and their networks in protein structures. J Chem Inf Model 2012; 52:1865-74. [PMID: 22721491 DOI: 10.1021/ci300213c] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A versatile method to directly identify and analyze short- or long-range coupled or communicating residues in a protein conformational ensemble is of extreme relevance to achieve a complete understanding of protein dynamics and structural communication routes. Here, we present xPyder, an interface between one of the most employed molecular graphics systems, PyMOL, and the analysis of dynamical cross-correlation matrices (DCCM). The approach can also be extended, in principle, to matrices including other indexes of communication propensity or intensity between protein residues, as well as the persistence of intra- or intermolecular interactions, such as those underlying protein dynamics. The xPyder plugin for PyMOL 1.4 and 1.5 is offered as Open Source software via the GPL v2 license, and it can be found, along with the installation package, the user guide, and examples, at http://linux.btbs.unimib.it/xpyder/.
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Affiliation(s)
- Marco Pasi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, P.zza della Scienza 2, 20126 Milan, Italy
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12
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Lee Y, Mick J, Furdui C, Beamer LJ. A coevolutionary residue network at the site of a functionally important conformational change in a phosphohexomutase enzyme family. PLoS One 2012; 7:e38114. [PMID: 22685552 PMCID: PMC3369874 DOI: 10.1371/journal.pone.0038114] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 05/01/2012] [Indexed: 11/26/2022] Open
Abstract
Coevolution analyses identify residues that co-vary with each other during evolution, revealing sequence relationships unobservable from traditional multiple sequence alignments. Here we describe a coevolutionary analysis of phosphomannomutase/phosphoglucomutase (PMM/PGM), a widespread and diverse enzyme family involved in carbohydrate biosynthesis. Mutual information and graph theory were utilized to identify a network of highly connected residues with high significance. An examination of the most tightly connected regions of the coevolutionary network reveals that most of the involved residues are localized near an interdomain interface of this enzyme, known to be the site of a functionally important conformational change. The roles of four interface residues found in this network were examined via site-directed mutagenesis and kinetic characterization. For three of these residues, mutation to alanine reduces enzyme specificity to ∼10% or less of wild-type, while the other has ∼45% activity of wild-type enzyme. An additional mutant of an interface residue that is not densely connected in the coevolutionary network was also characterized, and shows no change in activity relative to wild-type enzyme. The results of these studies are interpreted in the context of structural and functional data on PMM/PGM. Together, they demonstrate that a network of coevolving residues links the highly conserved active site with the interdomain conformational change necessary for the multi-step catalytic reaction. This work adds to our understanding of the functional roles of coevolving residue networks, and has implications for the definition of catalytically important residues.
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Affiliation(s)
- Yingying Lee
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Jacob Mick
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Cristina Furdui
- Department of Internal Medicine, Wake Forest University Health Sciences Winston-Salem, North Carolina, United States of America
| | - Lesa J. Beamer
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
- * E-mail:
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13
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Papaleo E, Renzetti G, Tiberti M. Mechanisms of intramolecular communication in a hyperthermophilic acylaminoacyl peptidase: a molecular dynamics investigation. PLoS One 2012; 7:e35686. [PMID: 22558199 PMCID: PMC3338720 DOI: 10.1371/journal.pone.0035686] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 03/21/2012] [Indexed: 11/25/2022] Open
Abstract
Protein dynamics and the underlying networks of intramolecular interactions and communicating residues within the three-dimensional (3D) structure are known to influence protein function and stability, as well as to modulate conformational changes and allostery. Acylaminoacyl peptidase (AAP) subfamily of enzymes belongs to a unique class of serine proteases, the prolyl oligopeptidase (POP) family, which has not been thoroughly investigated yet. POPs have a characteristic multidomain three-dimensional architecture with the active site at the interface of the C-terminal catalytic domain and a β-propeller domain, whose N-terminal region acts as a bridge to the hydrolase domain. In the present contribution, protein dynamics signatures of a hyperthermophilic acylaminoacyl peptidase (AAP) of the prolyl oligopeptidase (POP) family, as well as of a deletion variant and alanine mutants (I12A, V13A, V16A, L19A, I20A) are reported. In particular, we aimed at identifying crucial residues for long range communications to the catalytic site or promoting the conformational changes to switch from closed to open ApAAP conformations. Our investigation shows that the N-terminal α1-helix mediates structural intramolecular communication to the catalytic site, concurring to the maintenance of a proper functional architecture of the catalytic triad. Main determinants of the effects induced by α1-helix are a subset of hydrophobic residues (V16, L19 and I20). Moreover, a subset of residues characterized by relevant interaction networks or coupled motions have been identified, which are likely to modulate the conformational properties at the interdomain interface.
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Affiliation(s)
- Elena Papaleo
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.
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