Isolation, sequence and transcription of the gene encoding the photosystem II chlorophyll-binding protein, CP-47, in the cyanobacterium Anabaena 7120

Abstract

The psbB gene from the cyanobacterium Anabaena 7120 was cloned and its nucleotide sequence determined. This gene codes for the photosystem II chlorophyll-binding protein CP-47. We identified an open reading frame of 1527 bases that can code for a polypeptide with a predicted molecular weight of 56,254. Expression of the psbB gene in Anabaena 7120 results in two transcripts that begin 302 or 238 bp upstream of the open reading frame and both end 288 bp downstream following a 21 bp inverted repeat. We also show that the levels of these psbB gene transcripts as well as those of the glnA, rbcLS, and psbA genes, in RNA prepared from whole filaments, remain constant during heterocyst differentiation.