ClustalW multiple-sequence alignment of NrdH and NrdH-like bacterial proteins. Experimentally characterized S. aureus (SAU), E. coli (ECO), and C. ammoniagenes (CAM) NrdH orthologs are indicated in white boldface in black boxes. Redox-active residues are shown in gray boxes. Identical residues are indicated by asterisks, highly similar residues are indicated by colons, and weakly similar residues are indicated by dots (all shown in boldface type). SEP, Staphylococcus epidermidis; SHA, S. haemolyticus; SWA, Staphylococcus warneri; BAN, B. anthracis; BWE, Bacillus weihenstephanensis; BCO, Bacillus coahuilensis; Bsp, Bacillus sp. NRRL B-14911; STY, S. Typhimurium; DZE, Dickeya zeae; AGR, Agrobacterium tumefaciens; BME, Brucella melitensis; BLO, Bifidobacterium longum; MTU, M. tuberculosis; AOD, Actinomyces odontolyticus; LAC, Lactococcus lactis; SPY, S. pyogenes; SPN, Streptococcus pneumoniae; SAG, Streptococcus agalactiae; EFA, Enterococcus faecalis; EFE, Enterococcus faecium; LPL, Lactobacillus plantarum; LSA, Lactobacillus sakei. GenBank accession numbers of the NrdH proteins shown are listed in Table S1 in the supplemental material.