Uroporphyrin-III C-methyltransferase, plant (IPR012383)

Short name: Uropor_MeTrfase_pln

Overlapping homologous superfamilies

Family relationships



Uroporphyrin-III C-methyltransferase (S-Adenosyl-L-methionine:uroporphyrinogen III methyltransferase, SUMT), an enzyme of the sirohaem and cobalamin biosynthetic pathway, catalyses C methylation of uroporphyrinogen III (EC: [PMID: 1856165, PMID: 1906874]. It transfers two methyl groups from S-adenosyl-L-methionine to the C-2 and C-7 atoms of uroporphyrinogen III to yield precorrin-2 via the intermediate formation of precorrin-1. SUMT is the first enzyme committed to the biosynthesis of either sirohaem or cobalamin (vitamin B12) rather than haem, and precorrin-2 is a common intermediate in the biosynthesis of corrinoids such as vitamin B12, sirohaem and coenzyme F430.

Members of this family represent a separate, plant-specific group of SUMT (also called UPM). They are characterised by an additional unique N-terminal domain of unknown function, and therefore greater length than the canonical SUMTs. Part of this N-terminal domain resembles a transit peptide for localisation to mitochondria or plastids [PMID: 9006913]. The protein produced by in vitro expression is able to enter isolated intact chloroplasts but not mitochondria [PMID: 9006913].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.