Linked Life Data

1390660

Source:http://linkedlifedata.com/resource/pubmed/id/1390660

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
1992-10-26
pubmed:abstractText
An X-ray structure analysis of a crystal of mutant Asp229----Ala of cyclodextrin glycosyltransferase from Bacillus circulans (Ec 2.4.1.19) that had been shortly exposed to beta-cyclodextrin showed density corresponding to a maltose bound at the catalytic center. The crystal structure was refined to an R-factor of 18.7% at 2.5-A resolution. The catalytic center is defined by homology with the structurally known alpha-amylases and by the observation that mutants Asp229----Ala and Asp328----Ala are almost inactive. By model building, the density-defined maltose was extended to a full beta-cyclodextrin, which then indicated the general locations of seven subsites for glucosyl units. The catalytically competent residues Asp229, Glu257, and Asp328 are at the reducing end of the density-defined maltose. In the unligated wild-type structure, Glu257 and Asp328 form a 2.6-A hydrogen bond between their carboxylates in an arrangement that resembles those of the catalytically competent carboxylates in acid proteases. Presumably, the first catalytic step is an attack of the proton between Glu257 and Asp328 on the oxygen of the glycosidic bond.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8740-6
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Catalytic center of cyclodextrin glycosyltransferase derived from X-ray structure analysis combined with site-directed mutagenesis.
pubmed:affiliation
Institut für Organische Chemie und Biochemie, Universität, Freiburg im Breisgau, Germany.
pubmed:publicationType
Journal Article