zur: a Zn2+-responsive regulatory element of Staphylococcus aureus

A putative operon encoding a probable zinc-responsive regulatory element (z ur) and components of an ABC-type transporter (mreA mreB) have been charact erized in Staphylococcus aureus. The zur gene was inactivated but apparentl y this did not alter Zn2+ uptake. Expression of mreAB zur is at a low level under a range of ion conditions. To allow inducible expression of the oper on. a construct was made placing it under the control of the IPTG-inducible P-spac promoter. Using this approach, it was shown that zur is able to rep ress expression of the entire operon in a Zn2+-dependent manner. and that m reA and mreB are likely to be involved in high-affinity ion uptake. zur has no apparent role in pathogenicity in a lesion model of S. aureus infection .