Nucleotide sequence of the streptococcal pyrogenic exotoxin type B gene and relationship between the toxin and the streptococcal proteinase precursor.
The streptococcal pyrogenic exotoxin (SPE) type B-encoding structural gene, speB, was subcloned from a 4.5-kilobase streptococcal DNA insert onto a 2.4-kilobase insert, which was then sequenced. Studies indicated that a 1,194-base-pair open reading frame encoded a 398-amino-acid protein. Removal of the putative signal peptide resulted in a mature protein with 371 residues (molecular weight, 40,314), which was subsequently proteolyzed to yield a 253-residue breakdown product (molecular weight, 27,588). This processing was confirmed by amino-terminal sequencing of both the 40,314-molecular-weight protein and the breakdown product. Monte Carlo analysis indicated that SPE B was relatively dissimilar to other members of the pyrogenic toxin family that also includes SPEs A and C, toxic shock syndrome toxin 1, and the staphylococcal enterotoxins. Comparison with the published amino acid sequence of streptococcal proteinase precursor as well as DNA hybridization experiments indicated that SPE B is a variant of this protein even though the particular gene sequenced did not encode a proteolytically active molecule.
Department of Microbiology, Medical School, University of Minnesota, Minneapolis 55455.
A R
AR
Hauser
P M
PM
Schlievert
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005098:Exotoxins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005798:Genes, Bacterial; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009010:Monte Carlo Method; D010447:Peptide Hydrolases / Q000378:metabolism; D011749:Pyrogens / Q000235:genetics*; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D012984:Software; D013297:Streptococcus pyogenes / Q000235:genetics*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D005098:Exotoxins; D008565:Membrane Proteins; D011749:Pyrogens; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin; D010447:Peptide Hydrolases