Expression and Purification Of The Cytoplasmic Domain of BlaR1 From Methicillin-Resistant Staphylococcus Aureus; poster

BLÁZQUEZ, B.; LLARRULL, L.I.; MOBASHERY, S.

Notre Dame, Indiana, EEUU

Jornada; Chemistry-Biology-Biochemistry Interface Retreat; 2010

University of Notre Dame

Staphylococcus aureus (MRSA) has emerged as a globally important pathogen that is resistant to all classes of commercially available beta-lactam antibiotics. The basis for resistance is acquisition of a pair of signal sensing/transducing systems that unleash two separate and complementary antibiotic-resistance mechanisms. One of this systems, the bla system involves the expression of the PC1 beta-lactamase, which hydrolysis the beta-lactam ring rendering the antibiotic ineffective. The expression of these antibiotic-resistance determinants is induced by the presence of the antibiotic in the milieu. The BlaR1 receptor has been implicated primarily in induction of beta-lactamase expression (bla operon). The antibiotic irreversibly acylates the extracellular sensor domain of BlaR1 (BlaRs). BlaRs responds to this acylation by a protein conformational change that would be transmitted to the cytoplasmic domain to activate it. It has been proposed that the cytoplasmic domain is a metallo-protease, activated in the presence of the antibiotic. All previous attempts to express the cytoplasmic domain of BlaR1 have failed. Here we report the expression of the cytoplasmic domain of BlaR1 as different fusion proteins, and the purification of some of these fusion proteins in the presence of detergents mixtures.