Tetrapyrrole methylase, subdomain 2 (IPR014776)
Short name: 4pyrrole_Mease_sub2
- Tetrapyrrole methylase (IPR000878)
- Diphthine synthase (IPR004551)
- Cobalamin (vitamin B12) biosynthesis CobM/CbiF, precorrin-4 C11-methyltransferase (IPR006362)
- Precorrin-3B C17-methyltransferase domain (IPR006363)
- Precorrin-2 C(20)-methyltransferase domain (IPR006364)
- Uroporphyrin-III C-methyltransferase (IPR006366)
- rRNA small subunit methyltransferase I (IPR008189)
- Precorrin-2 C(20)-methyltransferase (IPR012382)
- Uroporphyrin-III C-methyltransferase, plant (IPR012383)
- Sirohaem synthase (IPR012409)
- Cobalamin (vitamin B12) biosynthesis CobF, precorrin-6A synthase (IPR012797)
- Cobalamin (vitamin B12) biosynthesis, bifunctional CbiH/CbiC (IPR014422)
- Tetrapyrrole methylase superfamily (IPR035996)
Tetrapyrroles are large macrocyclic compounds derived from a common biosynthetic pathway [PMID: 11215515]. The end-product, uroporphyrinogen III, is used to synthesise a number of important molecules, including cobalamin (vitamin B12), haem, sirohaem, chlorophyll, coenzyme F430 and phytochromobilin [PMID: 17227226].
This entry represents the C-terminal subdomain 2 from several tetrapyrrole methylases, which consist of two non-similar domains. These enzymes catalyse the methylation of their substrates using S-adenosyl-L-methionine as a methyl source. Enzymes in this family include:
- Uroporphyrinogen III methyltransferase (EC:184.108.40.206) (SUMT), which catalyses the conversion of uroporphyrinogen III to precorrin-2 at the first branch-point of the tetrapyrrole synthesis pathway, directing the pathway towards cobalamin or sirohaem synthesis [PMID: 15522295].
- Precorrin-2 C20-methyltransferase CobI/CbiL (EC:220.127.116.11), which introduces a methyl group at C-20 on precorrin-2 to produce precorrin-3A during cobalamin biosynthesis. This reaction is key to the conversion of a porphyrin-type tetrapyrrole ring to a corrin ring [PMID: 17229157]. In some species, this enzyme is part of a bifunctional protein.
- Precorrin-4 C11-methyltransferase CobM/CbiF (EC:18.104.22.168), which introduces a methyl group at C-11 on precorrin-4 to produce precorrin-5 during cobalamin biosynthesis [PMID: 16866557].
- Sirohaem synthase CysG (EC:22.214.171.124), domains 4 and 5, which synthesizes sirohaem from uroporphyrinogen III, at the first branch-point in the tetrapyrrole biosynthetic pathway, directing the pathway towards sirohaem synthesis [PMID: 14595395].
- Diphthine synthase (EC:126.96.36.199), which carries out the methylation step during the modification of a specific histidine residue of elongation factor 2 (EF-2) during diphthine synthesis.
- G3DSA:3.30.950.10 (G3DSA:3.30.950.10)