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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
7-8
|
| pubmed:dateCreated |
1997-2-18
|
| pubmed:abstractText |
1,3-1,4-beta-D-glucan 4-glucanohydrolases (beta-glucanases) are synthesized in both plants and bacteria. The enzymes specifically hydrolyze beta-1,4 glycosyl bonds that are adjacent to beta-1,3 linkages in beta-glucan, a linear polysaccharide containing these bonds in an approximate ratio of 2.5:1. Here we review structural studies by X-ray crystallography of natural Bacillus beta-glucanases and engineered variants characterized by hybrid sequences, single-site mutations and circular permutations. In combination with biochemical data and site-directed mutagenesis, the crystallographic evidence permits the formulation of a likely reaction mechanism for the retaining Bacillus beta-glucanases. In addition, the shape of the active site channel, the known binding mode of a cellobioside epoxyalkyl inhibitor and the energy profile of the beta-glucan substrate explain the specificity of the enzymes for beta-glucan and the requirement for a beta-1,3 glycosyl bond next to the scissile bond. beta-Glucanases with circularly permuted sequences retain conformational stability, enzymatic activity and the native fold. The jellyroll tertiary structure of Bacillus beta-glucanases is remarkably stable, resisting changes in amino acid sequence, chain topology, ligand binding and crystal packing.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:issn |
1431-6730
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
377
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
447-54
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading | |
| pubmed:articleTitle |
Enzymology and folding of natural and engineered bacterial beta-glucanases studied by X-ray crystallography.
|
| pubmed:affiliation |
Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany.
|
| pubmed:publicationType |
Journal Article,
Review,
Research Support, Non-U.S. Gov't
|