Affiliation:
1. Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840,1 and
2. Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 731902
Abstract
ABSTRACT
Streptococcus pyogenes
produces several extracellular proteins, including streptococcal erythrogenic toxin B (SPE B), also known as streptococcal pyrogenic exotoxin B and streptococcal proteinase. Several reports suggest that SPE B contributes to the virulence associated with
S. pyogenes
; however, little is known about its regulation. Nucleotide sequence data revealed the presence, upstream of the
speB
gene, of a gene, designated
rgg
, that was predicted to encode a polypeptide similar to previously described positive regulatory factors. The putative Rgg polypeptide of
S. pyogenes
NZ131 consisted of 280 amino acids and had a predicted molecular weight of 33,246. To assess the potential role of Rgg in the production of SPE B, the
rgg
gene was insertionally inactivated in
S. pyogenes
NZ131, which resulted in markedly decreased SPE B production, as determined both by immunoblotting and caseinolytic activity on agar plates. However, the production of other extracellular products, including streptolysin O, streptokinase, and DNase, was not affected. Complementation of the
rgg
mutant with an intact
rgg
gene copy in
S. pyogenes
NZ131 could restore SPE B production and confirmed that the
rgg
gene product is involved in the production of SPE B.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Immunology,Microbiology,Parasitology