This family contains arginine deiminases, EC:3.5.3.6., enzymes that catalyse the reaction: arginine + H2O <=> citrulline + NH3. These enzymes belong to the amidinotranferase (AT) superfamily, which share the alpha/beta fold including structurally important residues, i.e buried hydrophobic residues, buried hydrophilic residues hydrogen-bonded with mainchain groups and a structural hallmark of three consecutive buried Gly residues near the C-terminus, conserved among these proteins [1-3].

1: The arginine deiminase pathway in Rhizobium etli: DNA sequence analysis and functional study of the arcABC genes. D'Hooghe I, Vander Wauven C, Michiels J, Tricot C, de Wilde P, Vanderleyden J, Stalon V; J Bacteriol 1997;179:7403-7409. PMID:9393705

2: A novel superfamily of enzymes that catalyze the modification of guanidino groups. Shirai H, Blundell TL, Mizuguchi K; Trends Biochem Sci 2001;26:465-468. PMID:11504612

3: Prediction of the structure and function of AstA and AstB, the first two enzymes of the arginine succinyltransferase pathway of arginine catabolism. Shirai H, Mizuguchi K; FEBS Lett 2003;555:505-510. PMID:14675764