An HlyB-type function is required for expression of the Enterococcus faecalis hemolysin/bacteriocin

Abstract

The nucleotide sequence of a 3,422-bp internal restriction fragment from the Enterococcus faecalis pADI 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 alphahemolysin 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.

Cytotoxic Effect of Hemolytic Culture Supernatant from Enterococcus faecalis on Mouse Polymorphonuclear Neutrophils and Macrophages

“…faecalis has been done (6,13). By comparison, very little is known of the cytotoxic activity of hemolysin produced by E. faecalis except that the virulence of high hemolysin-producing mutant strains is greater than the parent hemolytic strain in systemic infections in mice (11).…”

The biology of lantibiotics from the lacticin 481 group is coming of age

“…(1993); ; Siegers & Entian (1995); Stein et al ( , 2003Stein et al ( , 2005 LanX Skaugen et al (1994Skaugen et al ( , 1997Skaugen et al ( , 2002; Gilmore et al (1996); Rawlinson et al (2002) Lacticin 3147 Gilmore et al (1990Gilmore et al ( , 1994; Segarra et al (1991); Booth et al (1996); Gilmore et al (1996); Coburn et al (1999Coburn et al ( , 2004 (2003) expected to be at the cytosolic side of the membrane (Håvarstein et al, 1995;Franke et al, 1999). NukA was shown to directly interact both with the protease domain and with the membrane-spanning domain of NukT, whereas NukM binds to the ATP-binding and membrane-spanning domains of NukT Fig.…”

Virulence of enterococci

“…Nucleotide sequence determination for the E. faecalis cytolysin operon has revealed a complex determinant encoding five gene products (Fig. lb) (84,85,201). Several lines of evidence suggest that the E. faecalis cytolysin represents a new branch of the lantibiotic family, a group of small secreted proteins with bactericidal activity against gram-positive pathogens such as staphylococci, streptococci, and propionibacteria (198).…”

“…Several lines of evidence suggest that the E. faecalis cytolysin represents a new branch of the lantibiotic family, a group of small secreted proteins with bactericidal activity against gram-positive pathogens such as staphylococci, streptococci, and propionibacteria (198). Reading frames cylLl, cylL2, cyIM, and cyIB are relevant to expression of component L (84,85,117), whereas cylA is the only reading frame necessary for expression of component A (201).…”

“…lb). cyIB was the first gene encoding an ATP-binding cassette transporter reported for a gram-positive bacterium (84). ATP-binding cassette transporters are transmembrane systems that facilitate translocation of molecules with a high degree of substrate specificity and contain highly conserved ATP-binding motifs (70).…”