1gow: Difference between revisions
No edit summary |
No edit summary |
||
| Line 21: | Line 21: | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 16:16:23 2007'' | ||
Revision as of 17:11, 5 November 2007
|
BETA-GLYCOSIDASE FROM SULFOLOBUS SOLFATARICUS
OverviewOverview
Enzymes from hyperthermophilic organisms must operate at temperatures, which rapidly denature proteins from mesophiles. The structural basis of, this thermostability is still poorly understood. Towards a further, understanding of hyperthermostability, we have determined the crystal, structure of the beta-glycosidase (clan GH-1A, family 1) from the, hyperthermophilic archaeon Sulfolobus solfataricus at 2.6 A resolution., The enzyme is a tetramer with subunit molecular mass at 60 kDa, and, crystallises with half of the tetramer in the asymmetric unit. The, structure is a (betaalpha)8 barrel, but with substantial elaborations, between the beta-strands and alpha-helices in each repeat. The active site, occurs at the centre of the top face of the barrel and is connected to the, surface by a radial channel which becomes a blind-ended tunnel in the, tetramer, and probably acts as the binding site for extended, oligosaccharide substrates. Analysis of the structure reveals two features, which differ significantly from mesophile proteins; (1) an unusually large, proportion of surface ion-pairs involved in networks that cross-link, sequentially separate structures on the protein surface, and (2) an, unusually large number of solvent molecules buried in hydrophilic cavities, between sequentially separate structures in the protein core. These, factors suggest a model for hyperthermostability via resilience rather, than rigidity.
About this StructureAbout this Structure
1GOW is a Single protein structure of sequence from Sulfolobus solfataricus. Active as Beta-galactosidase, with EC number 3.2.1.23 Structure known Active Sites: CTA and CTB. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the beta-glycosidase from the hyperthermophilic archeon Sulfolobus solfataricus: resilience as a key factor in thermostability., Aguilar CF, Sanderson I, Moracci M, Ciaramella M, Nucci R, Rossi M, Pearl LH, J Mol Biol. 1997 Sep 5;271(5):789-802. PMID:9299327
Page seeded by OCA on Mon Nov 5 16:16:23 2007