Funk C, Schroder WP, Green BR, Renger G, Andersson B
The Intrinsic 22 Kda Protein Is a Chlorophyll-Binding Subunit of Photosystem-Ii
Febs Letters: 1994 342:261-266
The intrinsic 22 kDa polypeptide associated with photosystem II (psbS protein) was found to be able to bind chlorophyll. Extraction of isolated photosystem II membranes with octyl-thioglucopyranoside, followed by repetitive electrophoresis under partially denaturing conditions gave only one green band. It contained both chlorophyll a and chlorophyll b, exhibited an absorption maximum at 674 nm and a 77 K fluorescence peak at 675 Mn. The chIorophyll-protein band contained a single polypeptide of 22 kDa. Based on these results and on previous protein sequence comparisons, it is suggested that the psbS protein is a chlorophyll a/b binding polypeptide and should thus be denoted CP22.
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