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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1999-3-11
pubmed:databankReference
pubmed:abstractText
The crystal structure of plastocyanin from a green alga, Ulva pertusa, has been determined at 1.6-A resolution. At its copper site, U. pertusa plastocyanin has a distorted tetrahedral coordination geometry similar to other plastocyanins. In comparison with structures of plastocyanins reported formerly, a Cu(II)-Sdelta(Met92) bond distance (2.69 A) is shorter by about 0.2 A and a Cu(II)-Sgamma(Cys84) distance is longer by less than 0.1 A in U. pertusa plastocyanin. These subtle but significant differences are caused by the structural change at a His-Met loop (His87-Met92) due to an absence of a O(Asp85)-Ogamma(Ser88) hydrogen bond which is found in Enteromorpha prolifera plastocyanin. In addition, poplar and Chlamydomonas reinhardtii plastocyanins with a glutamine at residue 88 have a weak cation-pi interaction with Tyr83. This interaction lengthens the Cu(II)-Sdelta(Met92) bond of poplar and C. reinhardtii plastocyanins by 0.14 and 0.20 A, respectively. As a result of structural differences, U. pertusa plastocyanin has a less distorted geometry than the other plastocyanins. Thus, the cupric geometry is finely tuned by the interactions between residues 85 and 88 and between residues 83 and 88. This result implies that the copper site is more flexible than reported formerly and that the rack mechanism would be preferable to the entatic theory. The His-Met loop may regulate the electron transfer rate within the complex between plastocyanin and cytochrome f.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4225-30
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Novel insight into the copper-ligand geometry in the crystal structure of Ulva pertusa plastocyanin at 1.6-A resolution. Structural basis for regulation of the copper site by residue 88.
pubmed:affiliation
Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't