A rice gene encoding a novel isoform of translation elongation factor- 1β subunit (termed EF-1β2) was isolated and characterized. The gene comprises of eight exons, and encodes a 226-amino-acid protein. Expression of EF-1β2 mRNA is abundant in seeds and cultured cells, but is considerably low in the tissues of the rice seedling. Antiserum raised against an EF-1β2 synthetic peptide detected a protein with a relative molecular mass of about 32 kDa, indicating the EF-1β2 gene is actually expressed in rice tissues. EF-1β2 showed a close similarity to the cognate subunits from plant (β and β').