The Crystal Structure of a Streptomyces thermoviolaceus Thermophilic Chitinase Known for Its Refolding Efficiency
| Autor: | Constantinos E. Vorgias, P.H. Malecki, Wojciech Rypniewski, Magdalena Bejger |
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| Rok vydání: | 2020 |
| Předmět: |
Models
Molecular 0301 basic medicine Protein Folding Protein Conformation Crystallography X-Ray Protein Refolding lcsh:Chemistry chemistry.chemical_compound Protein structure Catalytic Domain TIM barrel glycoside hydrolase Disulfides lcsh:QH301-705.5 Spectroscopy Thermostability biology Chemistry Chitinases General Medicine Streptomyces Computer Science Applications chitinase α+β-domain Streptomyces thermoviolaceus Stereochemistry Article Catalysis Inorganic Chemistry Structure-Activity Relationship 03 medical and health sciences Chitin Hydrolase structure and function relationship Physical and Theoretical Chemistry Molecular Biology X-ray crystallography Binding Sites 030102 biochemistry & molecular biology Thermophile Organic Chemistry thermostability 030104 developmental biology lcsh:Biology (General) lcsh:QD1-999 Amino Acid Substitution TIM-barrel Chitinase biology.protein |
| Zdroj: | International Journal of Molecular Sciences International Journal of Molecular Sciences, Vol 21, Iss 2892, p 2892 (2020) Volume 21 Issue 8 |
| ISSN: | 1422-0067 |
| DOI: | 10.3390/ijms21082892 |
| Popis: | Analyzing the structure of proteins from extremophiles is a promising way to study the rules governing the protein structure, because such proteins are results of structural and functional optimization under well-defined conditions. Studying the structure of chitinases addresses an interesting aspect of enzymology, because chitin, while being the world&rsquo s second most abundant biopolymer, is also a recalcitrant substrate. The crystal structure of a thermostable chitinase from Streptomyces thermoviolaceus (StChi40) has been solved revealing a &beta /&alpha barrel (TIM-barrel) fold with an &alpha +&beta insertion domain. This is the first chitinase structure of the multi-chitinase system of S. thermoviolaceus. The protein is also known to refold efficiently after thermal or chemical denaturation. StChi40 is structurally close to the catalytic domain of psychrophilic chitinase B from Arthrobacter TAD20. Differences are noted in comparison to the previously examined chitinases, particularly in the substrate-binding cleft. A comparison of the thermophilic enzyme with its psychrophilic homologue revealed structural features that could be attributed to StChi40&rsquo s thermal stability: compactness of the structure with trimmed surface loops and unique disulfide bridges, one of which is additionally stabilized by S&ndash &pi interactions with aromatic rings. Uncharacteristically for thermophilic proteins, StChi40 has fewer salt bridges than its mesophilic and psychrophilic homologues. |
| Databáze: | OpenAIRE |
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