This family catalyses the synthesis of thymidine monophosphate (dTMP) from deoxyuridine monophosphate (dUMP). The physiological co-substrate has not yet been identified. Previous designation of this famliy as being thymidylate synthase from one paper, PMID:10436953, has been shown to be erroneous [1]. The proteins are uncharacterised.

1: Identifying two ancient enzymes in Archaea using predicted secondary structure alignment. Xu H, Aurora R, Rose GD, White RH; Nat Struct Biol. 1999;6:750-754. PMID:10426953

2: Quod erat demonstrandum? The mystery of experimental validation of apparently erroneous computational analyses of protein sequences. Iyer LM, Aravind L, Bork P, Hofmann K, Mushegian AR, Zhulin IB, Koonin EV; Genome Biol. 2001;2:RESEARCH0051. PMID:11790254