This family consists of several bacterial nicotine adenine dinucleotide glycohydrolase (NGA) proteins which appear to be specific to Streptococcus pyogenes. NAD glycohydrolase (NADase) is a potential virulence factor. Streptococcal NADase may contribute to virulence by its ability to cleave beta-NAD at the ribose-nicotinamide bond, depleting intracellular NAD pools and producing the potent vasoactive compound nicotinamide [1].

1: Molecular epidemiology of nga and NAD glycohydrolase/ADP-ribosyltransferase activity among Streptococcus pyogenes causing streptococcal toxic shock syndrome. Stevens DL, Salmi DB, McIndoo ER, Bryant AE; J Infect Dis 2000;182:1117-1128. PMID:10979908