Cofactor F430

It occurs in relatively high concentrations in archaea that are involved in reverse methanogenesis: these can contain up to 7% by weight of the nickel protein.

[4] The trivial name cofactor F430 was assigned in 1978 based on the properties of a yellow sample extracted from Methanobacterium thermoautotrophicum, which had a spectroscopic maximum at 430 nm.

[5] It was identified as the MCR cofactor in 1982[6] and the complete structure was deduced by X-ray crystallography and NMR spectroscopy.

[7] Coenzyme F430 features a reduced porphyrin in a macrocyclic ring system called a corphin.

Reduction involves ATP hydrolysis and electrons are relayed through two 4Fe-4S centres.

Structure of coenzyme M (HS-CoM)
Structure of coenzyme B (HS-CoB)
uroporphyrinogen III
dihydrosirohydrochlorin
sirohydrochlorin
Nickel(II)-sirohydrochlorin a,c-diamide is converted to seco-F430. It is traditional to depict only one of four Ni-N bonds.