IUBMB Enzyme Nomenclature


Accepted name: bacteriochlorophyllide d C-121-methyltransferase

Reaction: S-adenosyl-L-methionine + 8-ethyl-12-methyl-3-vinylbacteriochlorophyllide d = S-adenosyl-L-homocysteine + 8,12-diethyl-3-vinylbacteriochlorophyllide d

For diagram of reaction click here.

Other name(s): bchR (gene name)

Systematic name: S-adenosyl-L-methionine:8-ethyl-12-methyl-3-vinylbacteriochlorophyllide-d C-121-methyltransferase

Comments: This enzyme, found in green sulfur bacteria (Chlorobiaceae) and green flimentous bacteria (Chloroflexaceae), is a radical S-adenosyl-L-methionine (AdoMet) enzyme and contains a [4Fe-4S] cluster. It adds a methyl group at the C-121 position of bacteriochlorophylls of the c, d and e types. This methylation plays a role in fine-tuning the structural arrangement of the bacteriochlorophyll aggregates in chlorosomes and therefore directly influences the chlorosomes absorption properties.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Gomez Maqueo Chew, A., Frigaard, N.U. and Bryant, D.A. Bacteriochlorophyllide c C-82 and C-121 methyltransferases are essential for adaptation to low light in Chlorobaculum tepidum. J. Bacteriol. 189 (2007) 6176-6184. [PMID: 17586634]

[EC created 2016]

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