http://hdl.handle.net/2328/8390 Flinders' staff research in Microbiology, reportable as part of ERA, 2001- Sat, 25 May 2013 00:17:56 GMT 2013-05-25T00:17:56Z http://hdl.handle.net/2328/25947 Title: The staphylococcal QacR multidrug regulator binds a correctly spaced operator as a pair of dimers Authors: Grkovic, Steve; Brown, Melissa Hackett; Schumacher, Maria A; Brennan, Richard G; Skurray, Ronald Anthony Abstract: Expression of the Staphylococcus aureusplasmid-encoded QacA multidrug transporter is regulated by the divergently encoded QacR repressor protein. To circumvent the formation of disulfide-bonded degradation products, site-directed mutagenesis to replace the two cysteine residues in wild-type QacR was undertaken. Analysis of a resultant cysteineless QacR derivative indicated that it retained full DNA-binding activities in vivo and in vitro and continued to be fully proficient for the mediation of induction ofqacA expression in response to a range of structurally dissimilar multidrug transporter substrates. The cysteineless QacR protein was used in cross-linking and dynamic light-scattering experiments to show that its native form was a dimer, whereas gel filtration indicated that four QacR molecules bound per DNA operator site. The addition of inducing compounds led to the dissociation of the four operator-bound QacR molecules from the DNA as dimers. Binding of QacR dimers to DNA was found to be dependent on the correct spacing of the operator half-sites. A revised model proposed for the regulation ofqacA expression by QacR features the unusual characteristic of one dimer of the regulatory protein binding to each operator half-site by a process that does not appear to require the prior self-assembly of QacR into tetramers. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/2328/25947 2001-01-01T00:00:00Z http://hdl.handle.net/2328/9352 Title: Stable low-copy-number Staphylococcus aureus shuttle vectors Authors: Grkovic, Steve; Brown, Melissa Hackett; Hardie, Kate M; Firth, Neville; Skurray, Ronald Anthony Wed, 01 Jan 2003 00:00:00 GMT http://hdl.handle.net/2328/9352 2003-01-01T00:00:00Z http://hdl.handle.net/2328/9353 Title: Comparison of enrichment methods for the isolation of pyrene-degrading bacteria Authors: Gaskin, Sharyn Elizabeth; Bentham, Richard Henry Sat, 01 Jan 2005 00:00:00 GMT http://hdl.handle.net/2328/9353 2005-01-01T00:00:00Z http://hdl.handle.net/2328/9351 Title: Actinoalloteichus hymeniacidonis sp. nov., an actincomycete isolated from the marine sponge Hymeniacidon perleve Authors: Huang, Jianyu; Zhang, Haitao; Zheng, Wen; Luo, Hongli; Jin, Yan; Huang, Ying; Liu, Zhiheng; Zhang, Wei Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/2328/9351 2006-01-01T00:00:00Z