A Ferredoxin Disulfide Reductase Delivers Electrons to the to the Methanosarcina barkeri Class III Ribonucleotide Reductase

• Main Authors: Wei, Yifeng (Contributor), Li, Bin (Author), Prakash, Divya (Author), Ferry, James G. (Author), Elliott, Sean J. (Author), Stubbe, JoAnne (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Biology (Contributor), Massachusetts Institute of Technology. Department of Chemistry (Contributor)
• Format: Article
• Language: English
• Published: American Chemical Society (ACS), 2017-04-20T13:41:29Z.
• Subjects: Article
• Online Access: Get fulltext

Two subtypes of class III anaerobic ribonucleotide reductases (RNRs) studied so far couple the reduction of ribonucleotides to the oxidation of formate, or the oxidation of NADPH via thioredoxin and thioredoxin reductase. Certain methanogenic archaea contain a phylogenetically distinct third subtype of class III RNR, with distinct active-site residues. Here we report the cloning and recombinant expression of the Methanosarcina barkeri class III RNR and show that the electrons required for ribonucleotide reduction can be delivered by a [4Fe-4S] protein ferredoxin disulfide reductase, and a conserved thioredoxin-like protein NrdH present in the RNR operon. The diversity of class III RNRs reflects the diversity of electron carriers used in anaerobic metabolism.
Singapore. Agency for Science, Technology and Research
National Institutes of Health (U.S.) (Grant GM081393)