The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium
The psychrophilic cellulase, Cel5G, from the Antarctic bacterium Pseudoalteromonas haloplanktis is composed of a catalytic module (CM) joined to a carbohydrate-binding module (CBM) by an unusually long, extended and flexible linker region (LR) containing three loops closed by three disulfide bridges...
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Online Access: | http://dx.doi.org/10.1042/bj20070640 https://portlandpress.com/biochemj/article-pdf/407/2/293/649865/bj4070293.pdf |
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crportlandpress:10.1042/bj20070640 2024-09-15T17:42:53+00:00 The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium Sonan, Guillaume K. Receveur-Brechot, Véronique Duez, Colette Aghajari, Nushin Czjzek, Mirjam Haser, Richard Gerday, Charles 2007 http://dx.doi.org/10.1042/bj20070640 https://portlandpress.com/biochemj/article-pdf/407/2/293/649865/bj4070293.pdf en eng Portland Press Ltd. Biochemical Journal volume 407, issue 2, page 293-302 ISSN 0264-6021 1470-8728 journal-article 2007 crportlandpress https://doi.org/10.1042/bj20070640 2024-07-18T04:20:49Z The psychrophilic cellulase, Cel5G, from the Antarctic bacterium Pseudoalteromonas haloplanktis is composed of a catalytic module (CM) joined to a carbohydrate-binding module (CBM) by an unusually long, extended and flexible linker region (LR) containing three loops closed by three disulfide bridges. To evaluate the possible role of this region in cold adaptation, the LR was sequentially shortened by protein engineering, successively deleting one and two loops of this module, whereas the last disulfide bridge was also suppressed by replacing the last two cysteine residue by two alanine residues. The kinetic and thermodynamic properties of the mutants were compared with those of the full-length enzyme, and also with those of the cold-adapted CM alone and with those of the homologous mesophilic enzyme, Cel5A, from Erwinia chrysanthemi. The thermostability of the mutated enzymes as well as their relative flexibility were evaluated by differential scanning calorimetry and fluorescence quenching respectively. The topology of the structure of the shortest mutant was determined by SAXS (small-angle X-ray scattering). The data indicate that the sequential shortening of the LR induces a regular decrease of the specific activity towards macromolecular substrates, reduces the relative flexibility and concomitantly increases the thermostability of the shortened enzymes. This demonstrates that the long LR of the full-length enzyme favours the catalytic efficiency at low and moderate temperatures by rendering the structure not only less compact, but also less stable, and plays a crucial role in the adaptation to cold of this cellulolytic enzyme. Article in Journal/Newspaper Antarc* Antarctic Portland Press Biochemical Journal 407 2 293 302 |
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English |
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The psychrophilic cellulase, Cel5G, from the Antarctic bacterium Pseudoalteromonas haloplanktis is composed of a catalytic module (CM) joined to a carbohydrate-binding module (CBM) by an unusually long, extended and flexible linker region (LR) containing three loops closed by three disulfide bridges. To evaluate the possible role of this region in cold adaptation, the LR was sequentially shortened by protein engineering, successively deleting one and two loops of this module, whereas the last disulfide bridge was also suppressed by replacing the last two cysteine residue by two alanine residues. The kinetic and thermodynamic properties of the mutants were compared with those of the full-length enzyme, and also with those of the cold-adapted CM alone and with those of the homologous mesophilic enzyme, Cel5A, from Erwinia chrysanthemi. The thermostability of the mutated enzymes as well as their relative flexibility were evaluated by differential scanning calorimetry and fluorescence quenching respectively. The topology of the structure of the shortest mutant was determined by SAXS (small-angle X-ray scattering). The data indicate that the sequential shortening of the LR induces a regular decrease of the specific activity towards macromolecular substrates, reduces the relative flexibility and concomitantly increases the thermostability of the shortened enzymes. This demonstrates that the long LR of the full-length enzyme favours the catalytic efficiency at low and moderate temperatures by rendering the structure not only less compact, but also less stable, and plays a crucial role in the adaptation to cold of this cellulolytic enzyme. |
format |
Article in Journal/Newspaper |
author |
Sonan, Guillaume K. Receveur-Brechot, Véronique Duez, Colette Aghajari, Nushin Czjzek, Mirjam Haser, Richard Gerday, Charles |
spellingShingle |
Sonan, Guillaume K. Receveur-Brechot, Véronique Duez, Colette Aghajari, Nushin Czjzek, Mirjam Haser, Richard Gerday, Charles The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium |
author_facet |
Sonan, Guillaume K. Receveur-Brechot, Véronique Duez, Colette Aghajari, Nushin Czjzek, Mirjam Haser, Richard Gerday, Charles |
author_sort |
Sonan, Guillaume K. |
title |
The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium |
title_short |
The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium |
title_full |
The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium |
title_fullStr |
The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium |
title_full_unstemmed |
The linker region plays a key role in the adaptation to cold of the cellulase from an Antarctic bacterium |
title_sort |
linker region plays a key role in the adaptation to cold of the cellulase from an antarctic bacterium |
publisher |
Portland Press Ltd. |
publishDate |
2007 |
url |
http://dx.doi.org/10.1042/bj20070640 https://portlandpress.com/biochemj/article-pdf/407/2/293/649865/bj4070293.pdf |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Biochemical Journal volume 407, issue 2, page 293-302 ISSN 0264-6021 1470-8728 |
op_doi |
https://doi.org/10.1042/bj20070640 |
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Biochemical Journal |
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407 |
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2 |
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293 |
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302 |
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1810489674075996160 |