Cofactor F430

Cofactor F430
Identifiers
CAS number	73145-13-8 Y
PubChem	5460020
	Properties
Molecular formula	C 42H 51N 6NiO– 13
Molar mass	906.58014
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

F₄₃₀ is the prosthetic group of the enzyme methyl coenzyme M reductase. It is found only in methanogenic Archaea.^[1] This enzyme catalyzes the release of methane in the final step of methanogenesis:

CH
3–S–CoM + HS–CoB → CH
4 + CoB–S–S–CoM

Corphin in context

Nature uses multiple tetrapyrroles - hemes, chlorophyll, and cobalamin. F₄₃₀ is the most reduced tetrapyrrole in nature with only five double bonds. This particular tetrapyrrole derivative is called a corphin. Because of its relative lack of conjugated unsaturation, it is yellow, not the intense purple-red associated with more unsaturated tetrapyrroles. It is also the only tetrapyrrole derivative found in nature to contain nickel. Ni(II) is too small for the N4 binding site of the corphin, which causes the macrocycle to adopt a ruffled structure. Its structure was deduced by X-ray crystallography and NMR spectroscopy.^[2]

F430 occurs in particularly high concentrations in bacteria that are thought to be involved in reverse methanogenesis. Organisms that promote this remarkable reaction contain 7% by weight nickel protein.^[3]

References