An HlyB-type function is required for expression of the Enterococcus faecalis hemolysin/bacteriocin.
The nucleotide sequence of a 3,422-bp internal restriction fragment from the Enterococcus faecalis pAD1 hemolysin/bacteriocin-encoding region was determined. This fragment was associated with expression of hemolysin/bacteriocin component L and contained a 2,142-bp open reading frame. The inferred amino acid sequence revealed a protein which shared extensive similarity with HlyB of the Escherichia coli alpha-hemolysin operon. The inferred protein, CylB, was observed to be independently expressed in E. coli and capable of complementing an insertion mutation in the cloned hemolysin/bacteriocin operon in trans. Despite the extensive similarity to HlyB, CylB was incapable of complementing an insertion mutation in hlyB. Cytolysin determinants possessing an HlyB-type transport function are widely dispersed throughout gram-negative genera. We believe this to be the first example of an HlyB-type protein encoded within a cytolysin determinant from a gram-positive bacterium.
Gilmore
M S
MS
Department of Microbiology and Immunology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City 73190.
Segarra
R A
RA
Booth
M C
MC
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000096:biosynthesis*; D001483:Base Sequence; D003603:Cytotoxins / Q000235:genetics*; D013293:Enterococcus faecalis / Q000235:genetics*; D005816:Genetic Complementation Test; D006460:Hemolysin Proteins / Q000235:genetics*; D008969:Molecular Sequence Data
D001430:Bacteriocins; D003603:Cytotoxins; D006460:Hemolysin Proteins; D000255:Adenosine Triphosphate