Linked Life Data

8226982

Source:http://linkedlifedata.com/resource/pubmed/id/8226982

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
1993-12-13
pubmed:abstractText
The chaperone protein Hsc70 is an ATPase of unknown mechanism, although the crystal structure of the 44-kDa ATPase domain has been solved. This structure shows that the hydroxyl of threonine 204 is located close to the gamma-phosphate of ATP, in a position where it might be an intermediate phosphate acceptor in the hydrolysis reaction. We made two point mutations at residue 204 of Hsc70, threonine to valine (T204V) and threonine to glutamic acid (T204E). The wild-type ATPase domain had a Km for ATP of approximately 1 microM; the mutants had Km values of approximately 90 microM. The kcat values for the mutant proteins were also increased. After crystallization, the structures of the T204V and T204E proteins were solved and refined with data to 2.3- and 2.4-A resolution, respectively. The overall tertiary structure of the mutants showed little change from the wild type; however, significant changes were observed in the active site. Analysis of the structures suggested possible reasons for the changes in kinetic constants. Threonine 204 does not seem to be an obligatory intermediate phosphate acceptor in the hydrolysis reaction since the mutants retained appreciable ATPase activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24323-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Threonine 204 of the chaperone protein Hsc70 influences the structure of the active site, but is not essential for ATP hydrolysis.
pubmed:affiliation
Beckman Laboratories for Structural Biology, Department of Cell Biology, Stanford University School of Medicine, California 94305.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.