Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus
Psychrophilic enzymes play crucial roles in cold adaptation of microbes and provide useful models for studies of protein evolution, folding, and dynamic properties. We examined the crystal structure (2.2-Å resolution) of the psychrophilic β-glucosidase BglU, a member of the glycosyl hydrolase 1 (GH1...
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ftpubmed:oai:pubmedcentral.nih.gov:4807509 2023-05-15T13:30:39+02:00 Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus Miao, Li-Li Hou, Yan-Jie Fan, Hong-Xia Qu, Jie Qi, Chao Liu, Ying Li, De-Feng Liu, Zhi-Pei 2016-03-21 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4807509/ http://www.ncbi.nlm.nih.gov/pubmed/26801571 https://doi.org/10.1128/AEM.03158-15 en eng American Society for Microbiology http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4807509/ http://www.ncbi.nlm.nih.gov/pubmed/26801571 http://dx.doi.org/10.1128/AEM.03158-15 Copyright © 2016, American Society for Microbiology. All Rights Reserved. Enzymology and Protein Engineering Text 2016 ftpubmed https://doi.org/10.1128/AEM.03158-15 2016-09-25T00:02:03Z Psychrophilic enzymes play crucial roles in cold adaptation of microbes and provide useful models for studies of protein evolution, folding, and dynamic properties. We examined the crystal structure (2.2-Å resolution) of the psychrophilic β-glucosidase BglU, a member of the glycosyl hydrolase 1 (GH1) enzyme family found in the cold-adapted bacterium Micrococcus antarcticus. Structural comparison and sequence alignment between BglU and its mesophilic and thermophilic counterpart enzymes (BglB and GlyTn, respectively) revealed two notable features distinct to BglU: (i) a unique long-loop L3 (35 versus 7 amino acids in others) involved in substrate binding and (ii) a unique amino acid, His299 (Tyr in others), involved in the stabilization of an ordered water molecule chain. Shortening of loop L3 to 25 amino acids reduced low-temperature catalytic activity, substrate-binding ability, the optimal temperature, and the melting temperature (Tm). Mutation of His299 to Tyr increased the optimal temperature, the Tm, and the catalytic activity. Conversely, mutation of Tyr301 to His in BglB caused a reduction in catalytic activity, thermostability, and the optimal temperature (45 to 35°C). Loop L3 shortening and H299Y substitution jointly restored enzyme activity to the level of BglU, but at moderate temperatures. Our findings indicate that loop L3 controls the level of catalytic activity at low temperatures, residue His299 is responsible for thermolability (particularly heat lability of the active center), and long-loop L3 and His299 are jointly responsible for the psychrophilic properties. The described structural basis for the cold adaptedness of BglU will be helpful for structure-based engineering of new cold-adapted enzymes and for the production of mutants useful in a variety of industrial processes at different temperatures. Text Antarc* antarcticus PubMed Central (PMC) Applied and Environmental Microbiology 82 7 2021 2030 |
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op_collection_id |
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English |
topic |
Enzymology and Protein Engineering |
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Enzymology and Protein Engineering Miao, Li-Li Hou, Yan-Jie Fan, Hong-Xia Qu, Jie Qi, Chao Liu, Ying Li, De-Feng Liu, Zhi-Pei Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus |
topic_facet |
Enzymology and Protein Engineering |
description |
Psychrophilic enzymes play crucial roles in cold adaptation of microbes and provide useful models for studies of protein evolution, folding, and dynamic properties. We examined the crystal structure (2.2-Å resolution) of the psychrophilic β-glucosidase BglU, a member of the glycosyl hydrolase 1 (GH1) enzyme family found in the cold-adapted bacterium Micrococcus antarcticus. Structural comparison and sequence alignment between BglU and its mesophilic and thermophilic counterpart enzymes (BglB and GlyTn, respectively) revealed two notable features distinct to BglU: (i) a unique long-loop L3 (35 versus 7 amino acids in others) involved in substrate binding and (ii) a unique amino acid, His299 (Tyr in others), involved in the stabilization of an ordered water molecule chain. Shortening of loop L3 to 25 amino acids reduced low-temperature catalytic activity, substrate-binding ability, the optimal temperature, and the melting temperature (Tm). Mutation of His299 to Tyr increased the optimal temperature, the Tm, and the catalytic activity. Conversely, mutation of Tyr301 to His in BglB caused a reduction in catalytic activity, thermostability, and the optimal temperature (45 to 35°C). Loop L3 shortening and H299Y substitution jointly restored enzyme activity to the level of BglU, but at moderate temperatures. Our findings indicate that loop L3 controls the level of catalytic activity at low temperatures, residue His299 is responsible for thermolability (particularly heat lability of the active center), and long-loop L3 and His299 are jointly responsible for the psychrophilic properties. The described structural basis for the cold adaptedness of BglU will be helpful for structure-based engineering of new cold-adapted enzymes and for the production of mutants useful in a variety of industrial processes at different temperatures. |
format |
Text |
author |
Miao, Li-Li Hou, Yan-Jie Fan, Hong-Xia Qu, Jie Qi, Chao Liu, Ying Li, De-Feng Liu, Zhi-Pei |
author_facet |
Miao, Li-Li Hou, Yan-Jie Fan, Hong-Xia Qu, Jie Qi, Chao Liu, Ying Li, De-Feng Liu, Zhi-Pei |
author_sort |
Miao, Li-Li |
title |
Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus |
title_short |
Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus |
title_full |
Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus |
title_fullStr |
Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus |
title_full_unstemmed |
Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus |
title_sort |
molecular structural basis for the cold adaptedness of the psychrophilic β-glucosidase bglu in micrococcus antarcticus |
publisher |
American Society for Microbiology |
publishDate |
2016 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4807509/ http://www.ncbi.nlm.nih.gov/pubmed/26801571 https://doi.org/10.1128/AEM.03158-15 |
genre |
Antarc* antarcticus |
genre_facet |
Antarc* antarcticus |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4807509/ http://www.ncbi.nlm.nih.gov/pubmed/26801571 http://dx.doi.org/10.1128/AEM.03158-15 |
op_rights |
Copyright © 2016, American Society for Microbiology. All Rights Reserved. |
op_doi |
https://doi.org/10.1128/AEM.03158-15 |
container_title |
Applied and Environmental Microbiology |
container_volume |
82 |
container_issue |
7 |
container_start_page |
2021 |
op_container_end_page |
2030 |
_version_ |
1766011120390242304 |