Nucleotide sequence of a bovine lens alpha A-crystallin cDNA.

We have determined the nucleotide sequence of a bovine lens alpha A2-crystallin cDNA clone, designated pBL alpha A2-1. The 793 bp cDNA insert contains coding information for the entire 173 amino acid alpha A2-crystallin polypeptide, as well as non-translated sequences located both upstream and downstream from the coding region. The coding sequences contained in pBL alpha A2-1 are at least 89% homologous with the corresponding sequences from other mammalian alpha A-crystallin genes, and are 78% homologous to the frog alpha A-crystallin coding region. In contrast, the downstream nontranslated sequences of the mammalian alpha A-crystallin transcripts show much greater sequence divergence, with the bovine sequences averaging 47% homology with the corresponding sequences from other mammalian species.