Sirohydrochlorin, a precursor of factor F430 biosynthesis in Methanobacterium thermoautotrophicum

Abstract
Factor F430 is a nickel‐containing coenzyme of methanogenic bacteria with porphinoid structure which is derived from uroporphyrinogen III. It is shown that sirohydrochlorin is metabolized by cell free extracts of Methanobacterium thermoautotrophicum to factor F430 demonstrating that this compound, or a reduced form of it, is an intermediate in the biosynthesis of F430, and not only of vitamin B12 and siroheme.