Linked Life Data

2884928

Source:http://linkedlifedata.com/resource/pubmed/id/2884928

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1987-7-10
pubmed:abstractText
Mutations in the uncA gene of Escherichia coli cause loss of both oxidative phosphorylation and ATP-driven generation of the transmembrane proton gradient. The uncA gene encodes the alpha-subunit of the F1-sector of the E. coli membrane proton-ATPase. F1-alpha-subunit from normal (unc+) E. coli binds ATP tightly (KD = 0.1 microM) and undergoes a large ATP-induced conformational change, but the functional role of the ATP-binding site is currently unknown. There is disagreement in the literature as to whether the ATP-binding site is present or lacking in F1-alpha-subunit from uncA mutant strains. One obstacle in studying this question is the difficulty of purifying mutant alpha-subunits in native form. In order to circumvent this difficulty we have studied ATP binding and ATP-induced conformational changes in mixtures of F1 subunits obtained by dissociating uncA mutant F1. Anti-alpha antibody was used in conjunction with immunoblotting to identify the alpha-subunits in the mixtures. Retention of native conformation by the alpha-subunits was demonstrated by the fact that the dissociated alpha-subunits were fully competent to repolymerize with other F1 subunits to yield intact F1 aggregate. The results show that, contrary to previous reports, alpha-subunits from three catalytically defective uncA mutants do indeed bind ATP and do undergo an ATP-induced conformational change. The binding affinity of alpha-subunit for ATP was lower than normal in each of the three mutants, but this is not likely to be a significant factor under physiological conditions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:volume
255
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
309-15
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
The defective proton-ATPase of uncA mutants of Escherichia coli: ATP-binding and ATP-induced conformational change in mutant alpha-subunits.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.