IUBMB Enzyme Nomenclature


Accepted name: R-phycocyanin α-cysteine84 phycourobilin lyase/isomerase

Reaction: [R-phycocyanin α-subunit]-Cys84-phycourobilin = apo-[R-phycocyanin α-subunit] + (2R,3E)-phycoerythrobilin

Other name(s): rpcG (gene name)

Systematic name: [R-phycocyanin α-subunit]-Cys84-phycourobilin:(2R,3E)-phycoerythrobilin lyase/isomerase

Comments: The enzyme, characterized from the cyanobacterium Synechococcus sp. WH8102, catalyses the covalent attachment of the phycobilin chromophore phycoerythrobilin to cysteine 84 of the α subunit of the phycobiliprotein R-phycocyanin and its isomerization to phycourobilin.

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


1. Blot, N., Wu, X.J., Thomas, J.C., Zhang, J., Garczarek, L., Bohm, S., Tu, J.M., Zhou, M., Ploscher, M., Eichacker, L., Partensky, F., Scheer, H. and Zhao, K.H. Phycourobilin in trichromatic phycocyanin from oceanic cyanobacteria is formed post-translationally by a phycoerythrobilin lyase-isomerase. J. Biol. Chem. 284 (2009) 9290-9298. [PMID: 19182270]

[EC created 2015]

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