Sequence of canine COL1A2 cDNA:: Nucleotide substitutions affecting the cyanogen bromide peptide map of the α2(I) chain

The alpha 2 chain of canine type I collagen was characterized with both sequence analysis of COL1A2 cDNA and chemical analysis of alpha 2(I) chains. The complete sequence of canine COL1A2 cDNA was determined from reverse-transcribed and polymerase chain reaction-amplified total RNA from cultured skin fibroblasts. Pepsin-digested and cyanogen bromide-digested type I collagen peptides were analyzed with chromatography, gel electrophoresis, and mass spectrometry. Identity between the sequences of canine and human COL1A2 cDNA was 90.9%, predicting conservation of the 3 cysteine residues required for C-propeptide registration and of cleavage sites for signal peptidase, procollagen N-proteinase, vertebrate collagenase, and procollagen C-proteinase. Conservation of all 50 lysine residues was also predicted, including preservation of the 1:2 asymmetry in the X:Y distribution of the 31 lysine residues in the alpha 2(I) triple helix. The human and canine sequences differed in the location of Y-position proline residues and the presence of two unique canine cyanogen bromide peptides, alpha 2 CB3b and alpha 2 CB3c,5. Knowledge of the conserved and unique features of canine COL1A2 will be valuable for analysis of the expression, synthesis, and structure of type I collagen as well as studies of canine osteogenesis imperfecta. (C) 1998 Academic Press.