title: Conservation of the biologically active portions of staphylococcal enterotoxins C1 and C2.
abstract: We determined the primary sequence of staphylococcal enterotoxin (SE) C2 by sequencing its cloned structural gene, entC2. The entC2 structural gene contains an 801-base-pair open reading frame which encodes a 266-amino-acid precursor with a molecular weight of 30,608. Mature SE C2, produced by removal of the signal peptide, contains 239 amino acids with a molecular weight of 27,531. A sequence comparison between SE C2 and SE C1 showed that the 167 carboxyl amino acids in both toxins were 100% conserved. In contrast, the 72 N-terminal residues were 10% divergent. This provides additional evidence that carboxyl regions of staphylococcal and streptococcal pyrogenic toxins determine shared biological activities and cross-reactive epitopes.
authors.affiliation: Department of Microbiology, Medical School, University of Minnesota, Minneapolis 55455.
authors.forename: G A
authors.initials: GA
authors.lastname: Bohach
authors.forename: P M
authors.initials: PM
authors.lastname: Schlievert
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000633:toxicity; D001483:Base Sequence; D004768:Enterotoxins / Q000235:genetics* / Q000302:isolation & purification / Q000633:toxicity; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D013211:Staphylococcus aureus / Q000235:genetics* / Q000502:physiology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004768:Enterotoxins; C034959:enterotoxin C, staphylococcal