Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1994-9-8
pubmed:abstractText
The degradation rate of the D1 polypeptide was measured in three Synechocystis PCC 6803 mutants in vivo. Mutations were introduced into a putative cleavage area of the D1 polypeptide (QEEET motif) and into the PEST-like area. PEST sequences are often found in proteins with a high turnover rate. The QEEET-motif mutants are CA1 [delta (E242-E244);Q241H] and E243K, and the third mutation, E229D, was directed to the PEST-like area. During high-light illumination (1500 mumol photons m-2 s-1) that induced photoinhibition of photosystem II (PSII), the half-life time of the D1 polypeptide in mutant E229D (t 1/2 = 35 min) was about twice as long as in AR (control strain) cells (t 1/2 = 19 min). In growth light (40 mumol photons m-2 s-1), the degradation rate of the D1 polypeptide in E229D and AR strains was the same (t 1/2 approximately 5 h). In growth light the D1 polypeptide was degraded faster in both QEEET-motif mutants than in the AR strain, but in photoinhibitory light the degradation rates were similar. According to these results, the highly conservative QEEET motif as such is not required for the proteolytic cut of the D1 polypeptide, but it does affect the rate of degradation. No simple correlation existed between the degradation rate of the D1 polypeptide and the susceptibility of PSII to photoinhibition in mutant and AR cells under our experimental conditions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0167-4412
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:geneSymbol
psbA
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
517-26
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Changes of amino acid sequence in PEST-like area and QEEET motif affect degradation rate of D1 polypeptide in photosystem II.
pubmed:affiliation
Department of Biology, University of Turku, Finland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't