Figure 5.

The MMR operon region from selected streptococcal species. The MMR operon in S. pyogenes and related streptococci is composed of a core group of genes involved in MMR, Holliday junction resolution and BER (mutS, mutL, ruvA, and tag). Indels are frequently found to supplement this basic genetic unit: MDR gene lmrP forms an additional part of this core in groups A, B, C, and G streptococci. Some indels encode proteins of unknown function, but others appear to encode potential virulence factors such as pauA (streptokinase) in S. uberis and the collagen-like adhesin in S. intermedius. For an extended list of streptococcal species that are differentiated by the presence or absence of lmrP, see Supplemental Table 1. The core genes of the streptococcal MMR operon are colored orange; MDP gene lmrP is magenta, and indels are red. The attachment site for SpyCI in S. pyogenes is indicated (attB). Legend for indel genes: glo—glyoxalase family protein; slaB—phospholipase A2 SlaB; pauA—streptokinase.