Nucleotide sequence of an abundant rice seed globulin: homology with the high molecular weight glutelins of wheat, rye and triticale

Abstract

A cDNA clone corresponding to a 19 kD salt-soluble globulin of rice (Oryza sativa L.) was isolated by screening a lambda gt11 expression library of endosperm mRNA with antibodies raised against the purified rice seed alpha-globulin. The cDNA contained a single large open reading frame encoding a putative globulin precursor of molecular weight of 21 kD. The polypeptide consists of 182 amino acids and is devoid of lysine residues. Computer analysis of the NH2-terminal sequence of the globulin precursor protein indicated the presence of an 18 amino acid signal peptide. Segments of the amino acid sequence of the rice globulin were homologous with sequences in high molecular weight glutelins of wheat. Antibodies specific for rice seed globulin also cross-reacted with seed proteins from wheat, rye and triticale.