Linked Life Data

10692547

Source:http://linkedlifedata.com/resource/pubmed/id/10692547

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2000-6-1
pubmed:abstractText
A Pathways analysis of the methylamine dehydrogenase-amicyanin-cytochrome c-551i protein electron transfer (ET) complex predicts two sets of ET pathways of comparable efficiency from the type I copper of amicyanin to the heme of cytochrome c-551i. In one pathway, the electron exits copper via the Cys(92) copper ligand, and in the other, it exits via the Met(98) copper ligand. If the Pathways algorithm is modified to include contributions from the anisotropy of metal-ligand coupling, independent of differences in copper-ligand bond length, then the pathways via Cys(92) are predicted to be at least 100-fold more strongly coupled than the pathways via any of the other copper ligands. All of the favored pathways via Cys(92) include a through-space jump from Cys(92) to the side chain of Tyr(30). To determine whether or not the pathways via Cys(92) are preferentially used for ET, Tyr(30) was changed to other amino acid residues by site-directed mutagenesis. Some mutant proteins were very unstable suggesting a role for Tyr(30) in stabilizing the protein structure. Y30F and Y30I mutant amicyanins could be isolated and analyzed. For the Y30I mutant, the modified Pathways analysis which favors ET via Cys(92) predicts a decrease in ET rate of at least two orders of magnitude, whereas the standard Pathways analysis predicts no change in ET rate since ET via Met(98) is not affected. Experimentally, the ET rates of the Y30I and Y30F mutants were indistinguishable from that of wild-type amicyanin. Likely explanations for these observations are discussed as are their implications for predicting pathways for ET reactions of metalloproteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
1457
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Tyr(30) of amicyanin is not critical for electron transfer to cytochrome c-551i: implications for predicting electron transfer pathways.
pubmed:affiliation
Department of Biochemistry, The University of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216-4505, USA. vdavidson@biochem.umsmed.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.