Advanced

Dimerisation and an increase in active site aromatic groups as adaptations to high temperatures: X-ray solution scattering and substrate-bound crystal structures of Rhodothermus marinus endoglucanase Cel12A

Crennell, SJ; Cook, D; Minns, A; Svergun, D; Andersen, RL and Nordberg Karlsson, Eva LU (2006) In Journal of Molecular Biology 356(1). p.57-71
Abstract
Cellulose, a polysaccharide consisting of beta-1,4-linked glucose, is the major component of plant cell walls and consequently one of the most abundant biopolymers on earth. Carbohydrate polymers such as cellulose are molecules with vast diversity in structure and function, and a multiplicity of hydrolases operating in concert are required for depolymerisation. The bacterium Rhodothermus marinus, isolated from shallow water marine hot springs, produces a number of carbohydrate-degrading enzymes including a family 12 cellulase Cel12A. The structure of R. marinus Cel12A in the ligand-free form (at 1.54 angstrom) and structures of RmCel12A after crystals were soaked in cellopentaose for two different lengths of time, have been determined. The... (More)
Cellulose, a polysaccharide consisting of beta-1,4-linked glucose, is the major component of plant cell walls and consequently one of the most abundant biopolymers on earth. Carbohydrate polymers such as cellulose are molecules with vast diversity in structure and function, and a multiplicity of hydrolases operating in concert are required for depolymerisation. The bacterium Rhodothermus marinus, isolated from shallow water marine hot springs, produces a number of carbohydrate-degrading enzymes including a family 12 cellulase Cel12A. The structure of R. marinus Cel12A in the ligand-free form (at 1.54 angstrom) and structures of RmCel12A after crystals were soaked in cellopentaose for two different lengths of time, have been determined. The shorter soaked complex revealed the conformation of unhydrolysed cellotetraose, while cellopentaose had been degraded more completely during the longer soak. Comparison of these structures with those of mesophilic family 12 cellulases in complex with inhibitors and substrate revealed that RmCel12A has a more extensive aromatic network in the active site cleft which ejects products after hydrolysis. The substrate structure confirms that during hydrolysis by family 12 cellulases glucose does not pass through a 2,5 B conformation. Small-angle X-ray scattering analysis of RmCel12A showed that the enzyme forms a loosely associated antiparallel dimer in solution, which may target the enzyme to the antiparallel polymer strands in cellulose. (c) 2005 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
SAXS, cellulase, endoglucanase, complex structure, thermostability
in
Journal of Molecular Biology
volume
356
issue
1
pages
57 - 71
publisher
Elsevier
external identifiers
  • wos:000234938600006
  • pmid:16343530
  • scopus:30344484545
ISSN
1089-8638
DOI
10.1016/j.jmb.2005.11.004
language
English
LU publication?
yes
id
50910b12-a741-4256-98f5-f407e898ba1c (old id 419399)
date added to LUP
2007-10-02 09:51:33
date last changed
2019-08-28 03:05:09
@article{50910b12-a741-4256-98f5-f407e898ba1c,
  abstract     = {Cellulose, a polysaccharide consisting of beta-1,4-linked glucose, is the major component of plant cell walls and consequently one of the most abundant biopolymers on earth. Carbohydrate polymers such as cellulose are molecules with vast diversity in structure and function, and a multiplicity of hydrolases operating in concert are required for depolymerisation. The bacterium Rhodothermus marinus, isolated from shallow water marine hot springs, produces a number of carbohydrate-degrading enzymes including a family 12 cellulase Cel12A. The structure of R. marinus Cel12A in the ligand-free form (at 1.54 angstrom) and structures of RmCel12A after crystals were soaked in cellopentaose for two different lengths of time, have been determined. The shorter soaked complex revealed the conformation of unhydrolysed cellotetraose, while cellopentaose had been degraded more completely during the longer soak. Comparison of these structures with those of mesophilic family 12 cellulases in complex with inhibitors and substrate revealed that RmCel12A has a more extensive aromatic network in the active site cleft which ejects products after hydrolysis. The substrate structure confirms that during hydrolysis by family 12 cellulases glucose does not pass through a 2,5 B conformation. Small-angle X-ray scattering analysis of RmCel12A showed that the enzyme forms a loosely associated antiparallel dimer in solution, which may target the enzyme to the antiparallel polymer strands in cellulose. (c) 2005 Elsevier Ltd. All rights reserved.},
  author       = {Crennell, SJ and Cook, D and Minns, A and Svergun, D and Andersen, RL and Nordberg Karlsson, Eva},
  issn         = {1089-8638},
  keyword      = {SAXS,cellulase,endoglucanase,complex structure,thermostability},
  language     = {eng},
  number       = {1},
  pages        = {57--71},
  publisher    = {Elsevier},
  series       = {Journal of Molecular Biology},
  title        = {Dimerisation and an increase in active site aromatic groups as adaptations to high temperatures: X-ray solution scattering and substrate-bound crystal structures of Rhodothermus marinus endoglucanase Cel12A},
  url          = {http://dx.doi.org/10.1016/j.jmb.2005.11.004},
  volume       = {356},
  year         = {2006},
}