Linked Life Data

8780528

Source:http://linkedlifedata.com/resource/pubmed/id/8780528

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
1996-10-16
pubmed:abstractText
A detailed characterization of RuvB protein-mediated ATP hydrolysis in the presence of RuvA protein has provided (a) the steady-state kinetic parameters of ATP hydrolysis within a RuvAB complex and (b) several insights into the mechanism of ATP hydrolysis and its coupling to translocation on DNA. In general, the RuvA protein increases the kcat and decreases the Km for the RuvB ATPase activity. DNA has a much greater effect on the kinetics of ATP hydrolysis when RuvA is present, consistent with a role of RuvA in facilitating the interaction between RuvB and DNA. Mechanistic clues come from deviations from normal steady-state kinetic behavior. A previously described burst of ATP hydrolysis, corresponding to two ATPs per RuvB hexamer [Marrione & Cox (1995) Biochemistry 34, 9809-9818], is still observed in the presence of RuvA protein. This suggests a functional asymmetry in the RuvB hexamer. There is a gradual attenuation of ATP hydrolysis when RuvB protein, alone or in the presence of RuvA protein, hydrolyzes ATP at ATP concentrations below the Km. The attenuation is observed even though an ATP regeneration system is present. ATP hydrolysis simply halts after a limited number of turnovers. The attenuation is reversible, and the effects of RuvA protein, DNA, and additional ATP in reversing the effect provide evidence for a complex array of allosteric interactions operating within the RuvB hexameric helicase. We propose a model in which individual subunits in a RuvB hexamer are functionally paired, with the three pairs moving sequentially and cooperatively through a multistep ATP hydrolytic cycle.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11228-38
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Allosteric effects of RuvA protein, ATP, and DNA on RuvB protein-mediated ATP hydrolysis.
pubmed:affiliation
Department of Biochemistry, College of Agriculture and Life Sciences, University of Wisconsin, Madison 53706, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't