Related Experiment Video
Updated: Jul 9, 2026

Structural Biology and Analytical Chemistry Approaches for Characterizing C-Glycoside Metabolic Enzymes in Human Gut Microbiota
Published on: May 23, 2025
Characterization of the NAD-glycohydrolase in streptococcal strains
Ichiro Tatsuno1, Jun Sawai2, Akira Okamoto2
1Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
Abstract:
The NADase (Nga) of group A streptococci (GAS) has been implicated in the pathogenesis of diseases such as streptococcal toxic shock-like syndrome (STSS) and necrotizing fasciitis. In this study we found that the proportion of NADase-positive strains among clinical isolates in Japan has increased over time. The GAS strains studied could be divided into three groups: strains lacking NADase activity, strains with low NADase activity, and strains with high NADase activity. The older strains, isolated before 1989, belonged to the 'no activity' group. Analysis using GST-Nga recombinants revealed that nga alleles of representative older strains encode inactive Nga. Mutational analysis of the GST-Nga recombinants suggested that residue 330 could be associated with reduced activity, based upon deduced amino acid sequences. We also investigated NADase activity of streptococcal strains other than GAS. All group G streptococcal isolates from STSS patients possessed nga genes encoding active enzymes.
Related Concept Videos
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Protein Glycosylation
Glycosylation occurs in...
Protein Folding Quality Check in the RER
Peptidoglycan Synthesis
Proteoglycans