Linked Life Data

8380418

Source:http://linkedlifedata.com/resource/pubmed/id/8380418

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-2-5
pubmed:abstractText
The structural properties of the iron-sulfur centers of photosystem I (PSI) from the cyanobacterium Synechocystis 6803 have been investigated by EPR spectrometry. The stoichiometry of centers A, B, and X, determined by EPR intensity measurements, gives direct evidence for center X being a [4Fe-4S] center in the native system and for the core reaction center protein being a dimer. The directions of the magnetic axes of centers A, B, and X were accurately determined by EPR experiments carried out on membrane fragments oriented on thin Mylar films. These directions are very similar to those previously reported for plants and algae. To get a detailed description of the relative arrangement of A and B, the magnetic interactions between these centers have been analyzed through numerical simulations of X-band and Q-band EPR spectra. The relative orientation of the magnetic axes deduced from these simulations is fully consistent with that given by oriented multilayer experiments. Numerical simulations of X-band and Q-band EPR spectra given by spinach PSI lead to a very similar set of structural parameters, which demonstrates that the functional unit of PSI is highly conserved in all photosynthetic organisms. Moreover, the results of these studies indicate that the A-B direction is close to the membrane normal, which supports a sequential electron transfer mechanism between the iron-sulfur centers in PSI.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
900-8
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Structural organization of the iron-sulfur centers in Synechocystis 6803 photosystem I. EPR study of oriented thylakoid membranes and analysis of the magnetic interactions.
pubmed:affiliation
Laboratoire d'Electronique des Milieux Condensés, URA 784, Centre National de la Recherche Scientifique (CNRS), Université de Provence, Centre St Jérôme, Marseille, France.
pubmed:publicationType
Journal Article