The lysostaphin endopeptidase resistance gene (epr) specifies modification of peptidoglycan cross bridges in Staphylococcus simulans and Staphylococcus aureus

Abstract

Staphylococcus simulans biovar staphylolyticus produces an extracellular glycylglycine endopeptidase (lysostaphin) that lyses other staphylococci by hydrolyzing the cross bridges in their cell wall peptidoglycans. The genes for endopeptidase (end) and endopeptidase resistance (epr) reside on plasmid pACK1. An 8.4-kb fragment containing end was cloned into shuttle vector pLI50 and was then introduced into Staphylococcus aureus RN4220. The recombinant S. aureus cells produced endopeptidase and were resistant to lysis by the enzyme, which indicated that the cloned fragment also contained epr. Treatments to remove accessory wall polymers (proteins, teichoic acids, and lipoteichoic acids) did not change the endopeptidase sensitivity of walls from strains of S. simulans biovar staphylolyticus or of S. aureus with and without epr. Immunological analyses of various wall fractions showed that there were epitopes associated with endopeptidase resistance and that these epitopes were found only on the peptidoglycans of epr ؉ strains of both species. Treatment of purified peptidoglycans with endopeptidase confirmed that resistance or susceptibility of both species was a property of the peptidoglycan itself. A comparison of the chemical compositions of these peptidoglycans revealed that cross bridges in the epr ؉ cells contained more serine and fewer glycine residues than those of cells without epr. The presence of the 8.4-kb fragment from pACK1 also increased the susceptibility of both species to methicillin.

Zoocin A immunity factor: a femA-like gene found in a group C streptococcus

“…zooepidemicus strains, or between zif containing and non-zif containing S. gordonii DL1 transformants ( Table 2). These results di¡er from those obtained for lif (epr) transformed staphylococcal strains [4,3] and suggest that unlike FemA, FemB and Lif, Zif is not involved in biosynthesis of the peptidoglycan precursor crosslink.…”

“…Peptidoglycan was puri¢ed from cultures of S. equi subsp. zooepidemicus 4881 and 8b and S. gordonii DL1 pVA 838 and pSB1311 grown in Columbia Broth (Difco) and analyzed for amino acid and amino sugar composition as previously described [3].…”

“…By contrast, the C-terminal region of zoocin A had homology to no other known sequence [2]. The lysostaphin-producing organism is known to be protected from the lytic action of its own glycylglycine endopeptidase by expression of a gene designated epr [3] or lif [4] which speci¢es for changes in the peptidoglycan cross bridges to contain more serine and fewer glycine residues. lif (epr) and lss (the lysostaphin structural gene) are encoded on plasmid pACK1 [5,6], lie proximal to and in opposite orien-tation to each other and are £anked on either side by insertion sequences [4].…”

Expression of the genes for lysostaphin and lysostaphin resistance in streptococci

“…A previously cloned 8.4-kb fragment that contained end and epr [10] was removed from the pLI50 backbone and subcloned into pVA838. The plasmid (pVA838-8.4) was introduced into S. equi subsp.…”

Identification of a haemolysin-like peptide with antibacterial activity using the draft genome sequence ofStaphylococcus epidermidisstrain A487

“…Staphylococci have been identified as producers of inhibitory peptides with particular ability to inhibit other staphylococcal strains (Jack et al, 1998;Daly et al, 2010) and exhibiting diverse chemical compositions and modes of action (Jack et al, 1998;Breukink & de Kruijff, 2006;Al-Mahrous et al, 2010). These include the lantibiotics (Jack et al, 1998) and the lysostaphins, members, respectively, of the bacteriocin and endopeptidase families (DeHart et al, 1995;Kokai-Kun et al, 2003). Staphylococcal cytolysins are a cluster of bioactive, sometimes antibacterial, proteins generally considered too toxic for use in humans (Dhople & Nagaraj, 2005;Verdon et al, 2008), due to their haemolytic activity (Fitton et al, 1980;Yianni et al, 1986;Janzon & Arvidson, 1990).…”