This domain is found in NodU from Rhizobium, CmcH from Nocardia lactamdurans and the bifunctional carbamoyltransferase TobZ from Streptoalloteichus tenebrarius. NodU a Rhizobium nodulation protein involved in the synthesis of nodulation factors has 6-O-carbamoyltransferase-like activity [1]. CmcH is involved in cephamycin (antibiotic) biosynthesis and has 3-hydroxymethylcephem carbamoyltransferase activity [2], EC:2.1.3.7 catalysing the reaction: Carbamoyl phosphate + 3-hydroxymethylceph-3-EM-4-carboxylate <=> phosphate + 3-carbamoyloxymethylcephem. TobZ functions as an ATP carbamoyltransferase and tobramycin carbamoyltransferase [3]. These proteins contain two domains, this is the smaller, C-terminal, domain.

1: Involvement of nodS in N-methylation and nodU in 6-O-carbamoylation of Rhizobium sp. NGR234 nod factors. Jabbouri S, Fellay R, Talmont F, Kamalaprija P, Burger U, Relic B, Prome JC, Broughton WJ; J Biol Chem 1995;270:22968-22973. PMID:7559434

2: Characterization of the cmcH genes of Nocardia lactamdurans and Streptomyces clavuligerus encoding a functional 3'-hydroxymethylcephem O-carbamoyltransferase for cephamycin biosynthesis. Coque JJ, Perez-Llarena FJ, Enguita FJ, Fuente JL, Martin JF, Liras P; Gene 1995;162:21-27. PMID:7557411

3: The O-carbamoyltransferase TobZ catalyzes an ancient enzymatic reaction. Parthier C, Gorlich S, Jaenecke F, Breithaupt C, Brauer U, Fandrich U, Clausnitzer D, Wehmeier UF, Bottcher C, Scheel D, Stubbs MT; Angew Chem Int Ed Engl. 2012;51:4046-4052. PMID:22383337