Iron-sulfur centers involved in methanogenic electron transfer in Methanobacterium thermoautotrophicum (delta-H).

Utilizing a subcellular particulate preparation from Methanobacterium thermoautotrophicum (delta-H) which contains all detectable methanogenic electron transfer activity, we present the results of the effects of the anaerobic addition of oxidized factor F420 and of methyl coenzyme M plus ATP on the EPR signals from reduced iron-sulfur centers and a rapidly-relaxing radical species. Based on these results, we report the existence of a minimum of three iron-sulfur centers which are capable of donating electrons to these cofactors.