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Bergmann J, Oksanen E, Ryde U. Combining crystallography with quantum mechanics. Curr Opin Struct Biol 2021; 72:18-26. [PMID: 34392061 DOI: 10.1016/j.sbi.2021.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/29/2021] [Accepted: 07/05/2021] [Indexed: 11/19/2022]
Abstract
In standard crystallographic refinement of biomacromolecules, the crystallographic raw data are supplemented by empirical restraints that ensure that the structure makes chemical sense. These restraints are typically accurate for amino acids and nucleic acids, but less so for cofactors, substrates, inhibitors, ligands and metal sites. In quantum refinement, this potential is replaced by more accurate quantum mechanical (QM) calculations. Several implementations have been presented, differing in the level of QM and whether it is used for the entire structure or only for a site of particular interest. It has been shown that the method can improve and correct errors in crystal structures and that it can be used to determine protonation and tautomeric states of various ligands and to decide what is really seen in the structure by refining different interpretations and using standard crystallographic and QM quality measures to decide which fits the structure best.
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Affiliation(s)
- Justin Bergmann
- Department of Theoretical Chemistry, Lund University, Chemical Centre, P. O. Box 124, SE-221 00 Lund, Sweden
| | - Esko Oksanen
- European Spallation Source ESS ERIC, P. O. Box 176, SE-221 00 Lund, Sweden
| | - Ulf Ryde
- Department of Theoretical Chemistry, Lund University, Chemical Centre, P. O. Box 124, SE-221 00 Lund, Sweden.
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2
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Fadel F, Zhao Y, Cachau R, Cousido-Siah A, Ruiz FX, Harlos K, Howard E, Mitschler A, Podjarny A. New insights into the enzymatic mechanism of human chitotriosidase (CHIT1) catalytic domain by atomic resolution X-ray diffraction and hybrid QM/MM. ACTA ACUST UNITED AC 2015; 71:1455-70. [PMID: 26143917 DOI: 10.1107/s139900471500783x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 04/21/2015] [Indexed: 11/10/2022]
Abstract
Chitotriosidase (CHIT1) is a human chitinase belonging to the highly conserved glycosyl hydrolase family 18 (GH18). GH18 enzymes hydrolyze chitin, an N-acetylglucosamine polymer synthesized by lower organisms for structural purposes. Recently, CHIT1 has attracted attention owing to its upregulation in immune-system disorders and as a marker of Gaucher disease. The 39 kDa catalytic domain shows a conserved cluster of three acidic residues, Glu140, Asp138 and Asp136, involved in the hydrolysis reaction. Under an excess concentration of substrate, CHIT1 and other homologues perform an additional activity, transglycosylation. To understand the catalytic mechanism of GH18 chitinases and the dual enzymatic activity, the structure and mechanism of CHIT1 were analyzed in detail. The resolution of the crystals of the catalytic domain was improved from 1.65 Å (PDB entry 1waw) to 0.95-1.10 Å for the apo and pseudo-apo forms and the complex with chitobiose, allowing the determination of the protonation states within the active site. This information was extended by hybrid quantum mechanics/molecular mechanics (QM/MM) calculations. The results suggest a new mechanism involving changes in the conformation and protonation state of the catalytic triad, as well as a new role for Tyr27, providing new insights into the hydrolysis and transglycosylation activities.
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Affiliation(s)
- Firas Fadel
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, 1 Rue Laurent Fries, 67404 Illkirch CEDEX, France
| | - Yuguang Zhao
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Oxford University, Roosevelt Drive, Headington, Oxford, England
| | - Raul Cachau
- Leidos Biomedical Research Inc. Advanced Biomedical Computer Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Alexandra Cousido-Siah
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, 1 Rue Laurent Fries, 67404 Illkirch CEDEX, France
| | - Francesc X Ruiz
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, 1 Rue Laurent Fries, 67404 Illkirch CEDEX, France
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Oxford University, Roosevelt Drive, Headington, Oxford, England
| | - Eduardo Howard
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, 1 Rue Laurent Fries, 67404 Illkirch CEDEX, France
| | - Andre Mitschler
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, 1 Rue Laurent Fries, 67404 Illkirch CEDEX, France
| | - Alberto Podjarny
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UdS, 1 Rue Laurent Fries, 67404 Illkirch CEDEX, France
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Goerigk L, Collyer CA, Reimers JR. Recommending Hartree–Fock Theory with London-Dispersion and Basis-Set-Superposition Corrections for the Optimization or Quantum Refinement of Protein Structures. J Phys Chem B 2014; 118:14612-26. [DOI: 10.1021/jp510148h] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Lars Goerigk
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Charles A. Collyer
- School
of Molecular Bioscience, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jeffrey R. Reimers
- Centre
for Quantum and Molecular Structure, College of Sciences, Shanghai University, Shanghai 200444, China
- School
of Physics and Advanced Materials, The University of Technology, Sydney, New South Wales 2007, Australia
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Goerigk L, Reimers JR. Efficient Methods for the Quantum Chemical Treatment of Protein Structures: The Effects of London-Dispersion and Basis-Set Incompleteness on Peptide and Water-Cluster Geometries. J Chem Theory Comput 2013; 9:3240-51. [DOI: 10.1021/ct400321m] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Lars Goerigk
- School of Chemistry, The University of Sydney, New South Wales 2006, Australia
| | - Jeffrey R. Reimers
- School of Chemistry, The University of Sydney, New South Wales 2006, Australia
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DiLabio GA. Computational modeling of extended systems. Theor Chem Acc 2012. [DOI: 10.1007/s00214-011-1067-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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