Ornithine transcarbamylases. Ordering of S-cyano peptides and location of characteristically reactive cysteinyl residues within the sequence.

The peptides produced by cleavage of the S-cyano derivatives of the ornithine transcarbamylases (ornithine carbamoyltransferase, 2.1.3.3) from bovine liver, Streptococcus faecalis ATCC 11,420, and Streptococcus faecium ATCC 8043 have been isolated and aligned. Their amino acid compositions and COOH-terminal sequences are reported. The COOH-terminal peptide (51 residues in the bovine enzyme; 66 residues in the bacterial enzymes) contains the essential sulfhydryl group.