This domain of unknown function has a PLP-dependent transferase-like fold. Its genomic context suggests that it may have a role in anaerobic vitamin B12 biosynthesis. This domain is often found at the C-terminus of proteins containing DUF4213, Pfam:PF13938. The structure of UnioProtKB:B8FUJ5, PDB:3l5o, suggests that the protein has an enolase N-terminal-like fold and this Rossmann-like C-terminal domain. Structural and bioinformatic analyses reveal partial similarities to Rossmann-like methyltransferases, with residues from the enolase-like fold combining to form a unique active site that is likely to be involved in the condensation or hydrolysis of molecules implicated in the synthesis of flavins, pterins or other siderophores. The protein may be playing a role in heavy-metal chelation [1].

1: Structure of the first representative of Pfam family PF04016 (DUF364) reveals enolase and Rossmann-like folds that combine to form a unique active site with a possible role in heavy-metal chelation. Miller MD, Aravind L, Bakolitsa C, Rife CL, Carlton D, Abdubek P, Astakhova T, Axelrod HL, Chiu HJ, Clayton T, Deller MC, Duan L, Feuerhelm J, Grant JC, Han GW, Jaroszewski L, Jin KK, Klock HE, Knuth MW, Kozbial P, Krishna SS, Kumar A, Marciano D, McMullan D, Morse AT, Nigoghossian E, Okach L, Reyes R, van den Bedem H, Weekes D, Xu Q, Hodgson KO, Wooley J, Elsliger MA, Deacon AM, Godzik A, Lesley SA, Wilson IA; Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010;66:1167-1173. PMID:20944207