Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1832526 (PCC)
 5,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A chlorophyll-protein complex has been isolated from the cyanobacterium Synechocystis sp. PCC 6803 that closely resembles higher plant photosystem II reaction centers in spectral properties. The Synechocystis complex has a pigment content of 5-7 chlorophyll a molecules:1 Cyt b559:2 pheophytins; an optical absorption redmost transition at approximately 675 nm; and a nonconservative circular dichroism red signal, with extrema at 682 (+) and 652 (-) nm. Upon illumination, the Synechocystis D1/D2/Cyt b559 complex accumulates reduced pheophytin. LDS-PAGE and/or immunoblotting showed the D1, D2, and Cyt b559 proteins, aggregated and degraded forms of D1 and possibly D2, and traces of ATP synthase and the CP47 photosystem II chlorophyll protein. The availability of such a Synechocystis preparation opens the way for employing site-directed mutagenesis in studying primary reactions of oxygenic photosynthesis.
 ...
PMID:Isolation and spectroscopic characterization of a plantlike photosystem II reaction center from the cyanobacterium Synechocystis sp. 6803. 772 12

Changes in composition of membrane proteins in Synechocystis PCC 6803 induced by the shift of light regime for photosynthetic growth were studied in relation to the regulation of PS I/PS II stoichiometry. Special attention was paid to the changes in abundance of proteins of PS I and PS II complexes. Composition was examined using a LDS-PAGE and a quantitative enzyme immunoassay. Abundance of PsaA/B polypeptides and the PsaC polypeptide of the PS I complex, on a per cell basis, increased under the light regime exciting preferentially PS II and decreased under the light regime exciting mainly PS I. Similar changes were observed with polypeptides of 18.5, 10 and 8.5 kDa. The abundance of other proteins associated with membranes, including PsbA polypeptide of the PS II complex, was fairly constant irrespective of light regime. These results are consistent with our previous observations with other strains of cyanophytes (Anabaena variabilis M2 and Synechocystis PCC 6714) that PS I is the variable component in changes in PS I/PS II stoichiometry in response to changing light regimes for photosynthesis.
...
PMID:Changes in composition of membrane proteins accompanying the regulation of PS I/PS II stoichiometry observed with Synechocystis PCC 6803. 2440 83