Streptococcus sanguinis is a cause of infective endocarditis and has been shown to require
a manganese transporter called SsaB for virulence and O 2 tolerance. Like certain other
pathogens, S. sanguinis possesses aerobic class Ib (NrdEF) and anaerobic class III (NrdDG)
ribonucleotide reductases (RNRs) that perform the essential function of reducing
ribonucleotides to deoxyribonucleotides. The accompanying paper (Makhlynets, O., Boal,
AK, Rhodes, DV, Kitten, T., Rosenzweig, AC, and Stubbe, J.(2014) J. Biol. Chem. 289, 6259 …