In enzymology, a 3-hydroxymethylcephem carbamoyltransferase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are carbamoyl phosphate and 3-hydroxymethylceph-3-em-4-carboxylate, whereas its two products are phosphate and 3-carbamoyloxymethylcephem.
This enzyme belongs to the family of transferases, that transfer one-carbon groups, specifically the carboxy- and carbamoyltransferases.
The systematic name of this enzyme class is carbamoyl-phosphate:3-hydroxymethylceph-3-em-4-carboxylate carbamoyltransferase.
This enzyme has at least one effector, ATP.