Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium
The gene archb encoding for the cell-bound chitobiase from the Antarctic Gram-positive bacterium Arthrobacter sp. TAD20 was cloned and expressed in Escherichia coli in a soluble form. The mature chitobiase ArChb possesses four functionally independent domains. a catalytic domain stabilized by Ca2+,...
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Language: | English |
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Academic Press Ltd
2001
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ftunivqespace:oai:espace.library.uq.edu.au:UQ:109455 2023-05-15T13:31:21+02:00 Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium Lonhienne, Thierry Zoidakis, Jérôme Vorgias, Constantinos E. Feller, Georges Gerday, Charles Bouriotis, Vassilis 2001-07-06 https://espace.library.uq.edu.au/view/UQ:109455 eng eng Academic Press Ltd doi:10.1006/jmbi.2001.4774 issn:0022-2836 Biochemistry & Molecular Biology chitobiase glycosyl hydrolase microcalorimetry psychrophile extremophile Beta-n-acetylglucosaminidase Molecular-cloning Escherichia-coli Sequence Purification Proteins Enzymes Acetylhexosaminidase Adaptation Stability Journal Article 2001 ftunivqespace https://doi.org/10.1006/jmbi.2001.4774 2020-08-04T06:33:20Z The gene archb encoding for the cell-bound chitobiase from the Antarctic Gram-positive bacterium Arthrobacter sp. TAD20 was cloned and expressed in Escherichia coli in a soluble form. The mature chitobiase ArChb possesses four functionally independent domains. a catalytic domain stabilized by Ca2+, a,galactose-binding domain and an immunoglobulin-like domain followed by a cell-wall anchorage signal, typical of cell-surface proteins from Gram-positive bacteria. Binding of saccharides was analyzed by differential scanning calorimetry, allowing to distinguish unequivocally the catalytic domain from the galactose-binding domain and to study binding specificities. The results su,,est that ArChb could play a role in bacterium attachment to natural hosts. Kinetic parameters of ArChb demonstrate perfect adaptation to catalysis at low temperatures, as shown by a low activation energy associated with unusually low K-m and high k(cat) values. Thermodependence of these parameters indicates that discrete amino acid substitutions in the catalytic center have optimized the thermodynamic properties of weak interactions involved in substrate binding at low temperatures. Microcalorimetry also reveals that heat-lability, a general trait of psychrophilic enzymes, only affects the active site domain of ArChb. (C) 2001 Academic Press. Article in Journal/Newspaper Antarc* Antarctic The University of Queensland: UQ eSpace Antarctic The Antarctic Anchorage Journal of Molecular Biology 310 2 291 297 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
English |
topic |
Biochemistry & Molecular Biology chitobiase glycosyl hydrolase microcalorimetry psychrophile extremophile Beta-n-acetylglucosaminidase Molecular-cloning Escherichia-coli Sequence Purification Proteins Enzymes Acetylhexosaminidase Adaptation Stability |
spellingShingle |
Biochemistry & Molecular Biology chitobiase glycosyl hydrolase microcalorimetry psychrophile extremophile Beta-n-acetylglucosaminidase Molecular-cloning Escherichia-coli Sequence Purification Proteins Enzymes Acetylhexosaminidase Adaptation Stability Lonhienne, Thierry Zoidakis, Jérôme Vorgias, Constantinos E. Feller, Georges Gerday, Charles Bouriotis, Vassilis Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium |
topic_facet |
Biochemistry & Molecular Biology chitobiase glycosyl hydrolase microcalorimetry psychrophile extremophile Beta-n-acetylglucosaminidase Molecular-cloning Escherichia-coli Sequence Purification Proteins Enzymes Acetylhexosaminidase Adaptation Stability |
description |
The gene archb encoding for the cell-bound chitobiase from the Antarctic Gram-positive bacterium Arthrobacter sp. TAD20 was cloned and expressed in Escherichia coli in a soluble form. The mature chitobiase ArChb possesses four functionally independent domains. a catalytic domain stabilized by Ca2+, a,galactose-binding domain and an immunoglobulin-like domain followed by a cell-wall anchorage signal, typical of cell-surface proteins from Gram-positive bacteria. Binding of saccharides was analyzed by differential scanning calorimetry, allowing to distinguish unequivocally the catalytic domain from the galactose-binding domain and to study binding specificities. The results su,,est that ArChb could play a role in bacterium attachment to natural hosts. Kinetic parameters of ArChb demonstrate perfect adaptation to catalysis at low temperatures, as shown by a low activation energy associated with unusually low K-m and high k(cat) values. Thermodependence of these parameters indicates that discrete amino acid substitutions in the catalytic center have optimized the thermodynamic properties of weak interactions involved in substrate binding at low temperatures. Microcalorimetry also reveals that heat-lability, a general trait of psychrophilic enzymes, only affects the active site domain of ArChb. (C) 2001 Academic Press. |
format |
Article in Journal/Newspaper |
author |
Lonhienne, Thierry Zoidakis, Jérôme Vorgias, Constantinos E. Feller, Georges Gerday, Charles Bouriotis, Vassilis |
author_facet |
Lonhienne, Thierry Zoidakis, Jérôme Vorgias, Constantinos E. Feller, Georges Gerday, Charles Bouriotis, Vassilis |
author_sort |
Lonhienne, Thierry |
title |
Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium |
title_short |
Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium |
title_full |
Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium |
title_fullStr |
Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium |
title_full_unstemmed |
Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium |
title_sort |
modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic antarctic bacterium |
publisher |
Academic Press Ltd |
publishDate |
2001 |
url |
https://espace.library.uq.edu.au/view/UQ:109455 |
geographic |
Antarctic The Antarctic Anchorage |
geographic_facet |
Antarctic The Antarctic Anchorage |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
doi:10.1006/jmbi.2001.4774 issn:0022-2836 |
op_doi |
https://doi.org/10.1006/jmbi.2001.4774 |
container_title |
Journal of Molecular Biology |
container_volume |
310 |
container_issue |
2 |
container_start_page |
291 |
op_container_end_page |
297 |
_version_ |
1766017649486069760 |