A full length of cDNA encoding SM22 alpha from chicken gizzard smooth muscle was cloned and sequenced. Cloned cDNA had a total length of 1214bp and contained a single open reading frame which encodes 200 amino acids with a calculated molecular weight 22214. The predicted amino acid sequence was in complete agreement with the sequence determined by Pearlstone et al. using Edman degradation method (J. Biol. Chem. 262:5985, 1987) except for two additional residues, isoleucine and serine at the C-terminus.