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Title: High-resolution crystal structure of a polyextreme GH43 glycosidase from Halothermothrix orenii with α-l-arabinofuranosidase activity

Abstract

The crystal structure of the H. orenii glycosidase was determined by molecular replacement and refined at 1.10 Å resolution. A gene from the heterotrophic, halothermophilic marine bacterium Halothermothrix orenii has been cloned and overexpressed in Escherichia coli. This gene encodes the only glycoside hydrolase of family 43 (GH43) produced by H. orenii. The crystal structure of the H. orenii glycosidase was determined by molecular replacement and refined at 1.10 Å resolution. As for other GH43 members, the enzyme folds as a five-bladed β-propeller. The structure features a metal-binding site on the propeller axis, near the active site. Based on thermal denaturation data, the H. orenii glycosidase depends on divalent cations in combination with high salt for optimal thermal stability against unfolding. A maximum melting temperature of 76°C was observed in the presence of 4 M NaCl and Mn{sup 2+} at pH 6.5. The gene encoding the H. orenii GH43 enzyme has previously been annotated as a putative α-l-arabinofuranosidase. Activity was detected with p-nitrophenyl-α-l-arabinofuranoside as a substrate, and therefore the name HoAraf43 was suggested for the enzyme. In agreement with the conditions for optimal thermal stability against unfolding, the highest arabinofuranosidase activity was obtained in the presence of 4 M NaClmore » and Mn{sup 2+} at pH 6.5, giving a specific activity of 20–36 µmol min{sup −1} mg{sup −1}. The active site is structurally distinct from those of other GH43 members, including arabinanases, arabinofuranosidases and xylanases. This probably reflects the special requirements for degrading the unique biomass available in highly saline aqueous ecosystems, such as halophilic algae and halophytes. The amino-acid distribution of HoAraf43 has similarities to those of mesophiles, thermophiles and halophiles, but also has unique features, for example more hydrophobic amino acids on the surface and fewer buried charged residues.« less

Authors:
 [1];  [2];  [3];  [4];  [1];  [2];  [3]; ;  [1];  [2]
  1. KTH Royal Institute of Technology, Stockholm (Sweden)
  2. (Sweden)
  3. Griffith University, Brisbane, QLD 4111 (Australia)
  4. (United States)
Publication Date:
OSTI Identifier:
22375715
Resource Type:
Journal Article
Resource Relation:
Journal Name: Acta crystallographica. Section F, Structural biology communications; Journal Volume: 71; Journal Issue: Pt 3; Other Information: PMCID: PMC4356313; PMID: 25760712; PUBLISHER-ID: tt5064; PUBLISHER-ID: S2053230X15003337; OAI: oai:pubmedcentral.nih.gov:4356313; Copyright (c) Hassan et al. 2015; This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CATIONS; CRYSTAL STRUCTURE; DISTRIBUTION; ESCHERICHIA COLI; METALS; RESOLUTION; SALTS; STABILITY; SUBSTRATES; SURFACES

Citation Formats

Hassan, Noor, Karolinska Institutet, Stockholm, Kori, Lokesh D., Baylor College of Medicine, Houston, TX 77030, Gandini, Rosaria, Karolinska Institutet, Stockholm, Patel, Bharat K. C., Divne, Christina, Tan, Tien Chye, E-mail: tantc@kth.se, and Karolinska Institutet, Stockholm. High-resolution crystal structure of a polyextreme GH43 glycosidase from Halothermothrix orenii with α-l-arabinofuranosidase activity. United States: N. p., 2015. Web. doi:10.1107/S2053230X15003337.
Hassan, Noor, Karolinska Institutet, Stockholm, Kori, Lokesh D., Baylor College of Medicine, Houston, TX 77030, Gandini, Rosaria, Karolinska Institutet, Stockholm, Patel, Bharat K. C., Divne, Christina, Tan, Tien Chye, E-mail: tantc@kth.se, & Karolinska Institutet, Stockholm. High-resolution crystal structure of a polyextreme GH43 glycosidase from Halothermothrix orenii with α-l-arabinofuranosidase activity. United States. doi:10.1107/S2053230X15003337.
Hassan, Noor, Karolinska Institutet, Stockholm, Kori, Lokesh D., Baylor College of Medicine, Houston, TX 77030, Gandini, Rosaria, Karolinska Institutet, Stockholm, Patel, Bharat K. C., Divne, Christina, Tan, Tien Chye, E-mail: tantc@kth.se, and Karolinska Institutet, Stockholm. Thu . "High-resolution crystal structure of a polyextreme GH43 glycosidase from Halothermothrix orenii with α-l-arabinofuranosidase activity". United States. doi:10.1107/S2053230X15003337.
@article{osti_22375715,
title = {High-resolution crystal structure of a polyextreme GH43 glycosidase from Halothermothrix orenii with α-l-arabinofuranosidase activity},
author = {Hassan, Noor and Karolinska Institutet, Stockholm and Kori, Lokesh D. and Baylor College of Medicine, Houston, TX 77030 and Gandini, Rosaria and Karolinska Institutet, Stockholm and Patel, Bharat K. C. and Divne, Christina and Tan, Tien Chye, E-mail: tantc@kth.se and Karolinska Institutet, Stockholm},
abstractNote = {The crystal structure of the H. orenii glycosidase was determined by molecular replacement and refined at 1.10 Å resolution. A gene from the heterotrophic, halothermophilic marine bacterium Halothermothrix orenii has been cloned and overexpressed in Escherichia coli. This gene encodes the only glycoside hydrolase of family 43 (GH43) produced by H. orenii. The crystal structure of the H. orenii glycosidase was determined by molecular replacement and refined at 1.10 Å resolution. As for other GH43 members, the enzyme folds as a five-bladed β-propeller. The structure features a metal-binding site on the propeller axis, near the active site. Based on thermal denaturation data, the H. orenii glycosidase depends on divalent cations in combination with high salt for optimal thermal stability against unfolding. A maximum melting temperature of 76°C was observed in the presence of 4 M NaCl and Mn{sup 2+} at pH 6.5. The gene encoding the H. orenii GH43 enzyme has previously been annotated as a putative α-l-arabinofuranosidase. Activity was detected with p-nitrophenyl-α-l-arabinofuranoside as a substrate, and therefore the name HoAraf43 was suggested for the enzyme. In agreement with the conditions for optimal thermal stability against unfolding, the highest arabinofuranosidase activity was obtained in the presence of 4 M NaCl and Mn{sup 2+} at pH 6.5, giving a specific activity of 20–36 µmol min{sup −1} mg{sup −1}. The active site is structurally distinct from those of other GH43 members, including arabinanases, arabinofuranosidases and xylanases. This probably reflects the special requirements for degrading the unique biomass available in highly saline aqueous ecosystems, such as halophilic algae and halophytes. The amino-acid distribution of HoAraf43 has similarities to those of mesophiles, thermophiles and halophiles, but also has unique features, for example more hydrophobic amino acids on the surface and fewer buried charged residues.},
doi = {10.1107/S2053230X15003337},
journal = {Acta crystallographica. Section F, Structural biology communications},
number = Pt 3,
volume = 71,
place = {United States},
year = {Thu Feb 19 00:00:00 EST 2015},
month = {Thu Feb 19 00:00:00 EST 2015}
}