A ferredoxin-dependent dihydropyrimidine dehydrogenase in Clostridium chromiireducens.
Dihydropyrimidine dehydrogenase (PydA) catalyzes the first step of the reductive pyrimidine degradation (Pyd) pathway in bacteria and eukaryotes, enabling pyrimidines to be utilized as substrates for growth. PydA homologs studied to date catalyze the reduction of uracil to dihydrouracil, coupled to the oxidation of NAD(P)H. Uracil reduction occurs at a flavin mononucleotide (FMN) site, and NAD(P)H oxidation occurs at a flavin adenine dinucleotide (FAD) site, with two ferredoxin domains thought to mediate inter-site electron transfer. Here, we report the biochemical characterization of a Clostridial PydA homolog (PydAc) from a Pyd gene cluster in the strict anaerobic bacterium Clostridium chromiireducens. PydAc lacks the FAD domain, and instead is able to catalyze uracil reduction using reduced methyl viologen or reduced ferredoxin as the electron source. Homologs of PydAc are present in Pyd gene clusters in many strict anaerobic bacteria, which use reduced ferredoxin as an intermediate in their energy metabolism.
['Wang|Feifei|F|', 'Wei|Yifeng|Y|', 'Lu|Qiang|Q|', 'Ang|Ee Lui|EL|', 'Zhao|Huimin|H|', 'Zhang|Yan|Y|']
D003001:Cloning, Molecular D003013:Clostridium D042943:Dihydrouracil Dehydrogenase (NADP) D004579:Electron Transport D057075:Enzyme Assays D005288:Ferredoxins D011994:Recombinant Proteins D014498:Uracil
Dihydropyrimidine dehydrogenase clostridium reductive pyrimidine degradation Pyrimidine ferredoxin Fe-S cluster