Nucleotide sequence of the enterotoxin B gene from Staphylococcus aureus

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Staphylococcus aureus is a significant pathogen.
• Enterotoxin B (entB) is a key virulence factor produced by S. aureus.
• Understanding the genetic basis of toxin production is crucial for developing control strategies.

Purpose of the Study:

• To determine the complete nucleotide sequence of the Staphylococcus aureus enterotoxin B gene (entB).
• To identify and characterize the 5' and 3' flanking regions of the entB gene.
• To analyze the genetic organization and regulatory elements associated with entB.

Main Methods:

• DNA sequencing of the enterotoxin B gene and flanking regions.
• Analysis of open reading frames (ORFs) to predict protein sequences.
• Comparison of deduced amino acid sequences with known enterotoxin B sequences.
• Identification of potential promoter and transcription termination signals.

Main Results:

• The complete nucleotide sequence of the entB gene was determined.
• An open reading frame encoding a 266-amino acid enterotoxin B precursor was identified, including a 27-amino acid signal peptide.
• The entB gene was found to be flanked by a promoter-like sequence and a transcription termination signal.
• Two downstream overlapping ORFs in the opposite orientation were also identified.
• The deduced amino acid sequence closely matched the known enterotoxin B sequence.

Conclusions:

• The genetic organization of the enterotoxin B gene provides a framework for understanding its expression.
• The identified signal sequence suggests a mechanism for protein secretion.
• Further characterization of flanking regions may reveal additional regulatory mechanisms controlling entB expression.