Linked Life Data

1510930

Source:http://linkedlifedata.com/resource/pubmed/id/1510930

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
1992-9-29
pubmed:abstractText
Previous experiments have shown that a Synechocystis sp. PCC 6803 mutant (delta psbO) lacking the extrinsic manganese-stabilizing protein (MSP) exhibits impaired, but significant levels of H2O-splitting activity [Burnap, R., & Sherman, L.A. (1991) Biochemistry 30, 440-446]. [14C]DCMU-binding experiments now show that the number and affinity of DCMU-binding sites (normalized to chlorophyll) are equivalent in delta psbO and the wild type, suggesting equal concentrations of assembled reaction centers. A similar conclusion is reached on the basis of measurements of PSII electron transport (DPC-supported DCPIP reduction) by mutant and wild-type thylakoids. The pattern of flash O2 yield by delta psbO cells measured with a bare platinum electrode exhibits a period four oscillation (with a maximum on the third flash), indicating that the H2O-splitting enzyme in delta psbO retains the basic mechanistic features found in normal cells. However, the amplitude of these signals is smaller and more highly damped than those obtained from wild-type cells, suggesting the absence of MSP results in a higher miss probability and/or a reduction in the number of centers competent in oxygen evolution. Analysis of the rise kinetics of the ampermeric signal on the bare platinum electrode indicates that the S3-[S4]-S0 transition is retarded by at least a factor of 5 in the mutant. Thermoluminescence emission peak temperatures indicate that the S2QA-, S2QB-, and S3QB-charge pairs are significantly more stable with respect to recombination in the mutant. The intensities of the thermoluminescence emissions are also significantly reduced in the mutant.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
31
pubmed:geneSymbol
psbO
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7404-10
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Oxygen yield and thermoluminescence characteristics of a cyanobacterium lacking the manganese-stabilizing protein of photosystem II.
pubmed:affiliation
Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't