title: Primary structure of the immunoglobulin J chain from the mouse.
abstract: The primary structure of the murine J chain was investigated by sequence analysis of the J chain cDNA inserts from two independently cloned chimeric plasmids. The sequence data showed that (i) the two cDNA inserts accounted for all but approximately 100 5' nucleotides of the J chain mRNA and (ii) the J chain mRNA encodes a prepeptide of at least 23 amino acids, a mature protein of 137 residues, and an untranslated 3' region of 707 nucleotides exclusive of the 3' poly(A) tract. The amino acid sequence deduced for the mature mouse J chain was found to be 74% identical with that previously determined for the human J chain. By analyzing the conserved features of the sequence, a two-domain structure was generated for the J chain which correlates well with its functions in the polymerization of IgM and IgA. Moreover, by comparing the homologies of the J and heavy chains in mouse and man, evidence was obtained that the structures involved in polymerization are the most conserved elements of immunoglobulin molecules.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D007144:Immunoglobulin J-Chains / Q000235:genetics*; D051379:Mice; D011487:Protein Conformation
chemical_list: D007144:Immunoglobulin J-Chains; D004247:DNA