FIG. 1.

S. pyogenes contains a single nox homologue. (A) The arrows represent the directions of transcription of open reading frames, which are contained within the same chromosomal region as nox. Information presented under the arrows describes the genes to which the open reading frames have the highest homology. A possible factor-independent terminator located 3′ of the ldh homologue was identified by the method of Brendel and Trifonov (5). (B) The S. pyogenes nox homologue (S.py.; GenBank accession no. AF101442) contains all of the signature residues characteristic of E. faecalis nox (E.f., GenBank accession no. X68847) (44) and S. pneumoniae nox (S.pn.; GenBank accession no. AF014458), including the cysteine sulfenic acid redox center, the NADH contact region (box 2), and FAD-binding regions (boxes 1 and 3).