Mouse immunoglobulin A: Nucleotide sequence of the structural gene for the α heavy chain derived from cloned cDNAs

The cDNAs complementary to mouse immunoglobulin α heavy chain mRNAs have been cloned into the PstI site of the plasmid vector pBR322. Recombinant plasmids have been identified by hybrid-arrested translation and purification of α heavy chain mRNA on DNA-DBM filters. The nucleotide sequence of the inserts encodes the constant and 3' untranslated regions of the α heavy chain mRNA. The CH3 domains of human and mouse α chains are highly homologous, including a 36 amino acid fragment not reported in the protein sequence (Robinson and Appella, 1980). As in the case of the μ secreted heavy chain, the α heavy chain contains a carboxy terminal piece of 20 amino acids.