Nucleotide sequence of a cDNA clone encoding the complete precursor for the "10-kilodalton" polypeptide of photosystem II from Chinese cabbage.

A cDNA (pBIFl1) clone corresponding to the complete “10-kD precursor polypeptide associated with the PSII was isolated from the inflorescence cDNA library of Chinese cabbage (Brassica campestris L. spp. pekinesis). The nucleotide sequence was determined using the dideoxynucleotide chain-termination method (Sanger et al., 1977) and the amino acid sequence was deduced (Table I). The cDNA i s composed of 581 nucleotides and a putative open reading frame of 423 bp, a 5’ untranslated sequence of 12 bp, and a 3’ noncoding region of 116 bp. The putative open reading frame encodes a protein of 141 amino acid residues (mo1 wt = 1,464.7) that contains 41 transit peptide residues. The mature protein is predicted to consist of 100 amino acid residues (mo1 wt = 10,383.10). The protein has a potential Asn-linked glycosylation site (Asn-Thr-Ser) located at position 135, which is probably the first amino acid that is outside the membrane-spanning region, immersed in the stroma of the thylakoid lumen (Gil-Gomez et al., 1991). Comparison of the predicted protein with the Protein Identification Resource protein data base (DNASIS software) shows 94.3 and 72.5% homology to Arabidopsis thaliana (Gil-Gomez et al., 1991) and spinach (Lautner et al., 1988) at the protein level, respectively.