Identification of a new gene in the chloroplast genome encoding a low‐molecular‐mass polypeptide of photosystem II complex

This is the authors' abstract. We don't add key points for this paper.

Low‐molecular‐mass polypeptides in spinach photosystem II membranes were separated by SDS‐polyacrylamide gel electrophoresis. The partial amino acid sequence of one of the polypeptides was determined. Comparison of this sequence with the entire nucleotide sequence of the tobacco chloroplast genome revealed that this polypeptide is encoded in the chloroplast genome. The gene for the polypeptide, designated as psbK, is located between the genes for tRNASer and tRNAGln in the large single‐copy region and oriented in the direction opposite to the tRNA genes. The amino acid sequence deduced from the gene indicates that the translation product consists of 98 amino acid residues and its 62nd residue corresponds to the amino‐terminus of the mature polypeptide. The putative polypeptide consists of 37 amino acid residues with a molecular mass of 4285 Da and has a single membrane‐spanning segment. Northern blot hybridization analysis revealed that psbK was transcribed in the chloroplast.