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EC 126.96.36.199 Details
coproporphyrinogen III + 2 S-adenosyl-L-methionine = protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5′-deoxyadenosine
oxygen-independent coproporphyrinogen-III oxidase, HemN, coproporphyrinogen III oxidase
coproporphyrinogen-III:S-adenosyl-L-methionine oxidoreductase (decarboxylating)
This enzyme differs from EC 188.8.131.52, coproporphyrinogen oxidase, by using S-adenosyl-L-methionine (AdoMet) instead of oxygen as oxidant. It occurs mainly in bacteria, whereas eukaryotes use the oxygen-dependent oxidase. The reaction starts by using an electron from the reduced form of the enzyme’s [4Fe-4S] cluster to split AdoMet into methionine and the radical 5′-deoxyadenosin-5′-yl. This radical initiates attack on the 2-carboxyethyl groups, leading to their conversion into vinyl groups. This conversion, —·CH-CH2-COO- → —CH=CH2 + CO2 + e- replaces the electron initially used.
created 2004, deleted 2016
184.108.40.206 created 1961, deleted 1982