Molecular cloning and sequence analysis of a water-soluble chlorophyll protein cDNA from Japanese radish

A cDNA encoding a water-soluble chlorophyll protein (WSCP) was cloned from Japanese radish (Raphanus sativus L. var. hortensis). The nucleotide sequence of the clone contains an open reading frame of 669 nucleotides encoding a Raphanus-WSCP of 222 amino acids. The 23 residues of the amino-terminal extension of Raphanus-WSCP may be a signal sequence targeting the endoplasmic reticulum, and the mature WSCP contains 199 residues. The homology alignment of the Raphanus-WSCP sequence with the other WSCPs and their related proteins revealed the significant identity to Brassica-WSCP (Class IIA), but a lesser homology to Lepidium-WSCP (Class IIB). Previously, we purified WSCP from the main vein of a Japanese radish, and reported the 26 N-terminal amino acid sequence (Shinashi et al. (2000) J Plant Physiol 157: 255-262). However, we have since found that the sequence is not identical to that deduced from the cDNA obtained. In this paper, we report a nucleotide sequence of a full-length cDNA encoding a WSCP from a Japanese radish, to fix the primary structure reported in our previous paper.