Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2005-12-20
pubmed:abstractText
The PsbU subunit of photosystem II (PSII) is one of three extrinsic polypeptides associated with stabilizing the oxygen evolving machinery of photosynthesis in cyanobacteria. We investigated the influence of PsbU on excitation energy transfer and primary photochemistry by spectroscopic analysis of a PsbU-less (or deltaPsbU) mutant. The absence of PsbU was found to have multiple effects on the excited state dynamics of the phycobilisome and PSII. DeltaPsbU cells exhibited decreased variable fluorescence when excited with light absorbed primarily by allophycocyanin but not when excited with light absorbed primarily by chlorophyll a. Fluorescence emission spectra at 77 K showed evidence for impaired energy transfer from the allophycocyanin terminal phycobilisome emitters to PSII. Picosecond fluorescence decay kinetics revealed changes in both allophycocyanin and PSII associated decay components. These changes were consistent with a decrease in the coupling of phycobilisomes to PSII and an increase in the number of closed PSII reaction centers in the dark-adapted deltaPsbU mutant. Our results are consistent with the assumption that PsbU stabilizes both energy transfer and electron transport in the PBS/PSII assembly.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16939-48
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:16363807-Anti-Bacterial Agents, pubmed-meshheading:16363807-Bacterial Proteins, pubmed-meshheading:16363807-Chlorophyll, pubmed-meshheading:16363807-Darkness, pubmed-meshheading:16363807-Electron Transport, pubmed-meshheading:16363807-Energy Transfer, pubmed-meshheading:16363807-Fluorescence, pubmed-meshheading:16363807-Gene Silencing, pubmed-meshheading:16363807-Kinetics, pubmed-meshheading:16363807-Light, pubmed-meshheading:16363807-Lincomycin, pubmed-meshheading:16363807-Mutagenesis, Insertional, pubmed-meshheading:16363807-Oxygen, pubmed-meshheading:16363807-Photochemistry, pubmed-meshheading:16363807-Photosystem II Protein Complex, pubmed-meshheading:16363807-Phycobilisomes, pubmed-meshheading:16363807-Spectrometry, Fluorescence, pubmed-meshheading:16363807-Synechocystis
pubmed:year
2005
pubmed:articleTitle
The PsbU subunit of photosystem II stabilizes energy transfer and primary photochemistry in the phycobilisome-photosystem II assembly of Synechocystis sp. PCC 6803.
pubmed:affiliation
Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't