Linked Life Data

21069401

Source:http://linkedlifedata.com/resource/pubmed/id/21069401

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2011-2-2
pubmed:abstractText
Sco is a red copper protein that plays an essential yet poorly understood role in the metalation of the Cu(A) center of cytochrome oxidase, and is stable in both the Cu(I) and Cu(II) forms. To determine which oxidation state is important for function, we constructed His135 to Met or selenomethionine (SeM) variants that were designed to stabilize the Cu(I) over the Cu(II) state. H135M was unable to complement a sco? strain of Bacillus subtilis, indicating that the His to Met substitution abrogated cytochrome oxidase maturation. The Cu(I) binding affinities of H135M and H135SeM were comparable to that of the WT and 100-fold tighter than that of the H135A variant. The coordination chemistry of the H135M and H135SeM variants was studied by UV/vis, EPR, and XAS spectroscopy in both the Cu(I) and the Cu(II) forms. Both oxidation states bound copper via the S atoms of C45, C49 and M135. In particular, EXAFS data collected at both the Cu and the Se edges of the H135SeM derivative provided unambiguous evidence for selenomethionine coordination. Whereas the coordination chemistry and copper binding affinity of the Cu(I) state closely resembled that of the WT protein, the Cu(II) state was unstable, undergoing autoreduction to Cu(I). H135M also reacted faster with H(2)O(2) than WT Sco. These data, when coupled with the complete elimination of function in the H135M variant, imply that the Cu(I) state cannot be the sole determinant of function; the Cu(II) state must be involved in function at some stage of the reaction cycle.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1432-1327
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
285-97
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
The essential role of the Cu(II) state of Sco in the maturation of the Cu(A) center of cytochrome oxidase: evidence from H135Met and H135SeM variants of the Bacillus subtilis Sco.
pubmed:affiliation
Division of Environmental and Biomolecular Systems, Oregon Health and Sciences University, 20000 NW Walker Road, Beaverton, OR 97006, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural