Polypeptides of the XXXX -evolving photosystem II complex. Immunological detection and biogenesis.

@entity3208 @entity2772 @entity1133 @entity26 @entity95 @entity2975 @entity214
@entity26 -evolving photosystem II complex was isolated from @entity2772 chloroplasts. The individual polypeptides of the complex were isolated from @entity3208 ( @entity214 )- @entity2975 gels and antibodies were raised in @entity95 against these polypeptides. After washing of the isolation complex by 0.8 M Tris to release the extrinsic proteins, a distinct diffused protein band was revealed at the position of 33 kDa in @entity214 gels containing 4 M @entity1133 . When this band was electroeluted from the gel and subsequently electrophoresed on @entity214 gels, three distinct protein bands became apparent. Antibodies raised against each one of these polypeptides cross-reacted with the other two polypeptides to varying degrees but not with the other subunits of the complex. The three polypeptides were denoted as "34," "33," and "32" kDa and the 33 being the herbicide-binding protein. Using the antibodies, the relative amounts of the photosystem II polypeptides were followed during greening of etiolated @entity2772 seedlings. While all three extrinsic polypeptides were present in etiolated leaves at relatively high amounts, the other polypeptides could not be detected prior to an approximate 6-h illumination period. Further illumination induced the appearance of all of the rest of the subunits in a relatively similar rate. The @entity26 evolution activity was developed parallel to the increase in the amounts of these polypeptides. Therefore, the assembly of the active photosystem II during greening is a two-step process in contrast with the photosystem I reaction center, which is assembled step by step, and the rest of the chloroplast protein complexes, which are assembled by a concerted mechanism.
