Session 6, Abstract 32
ASSESSING THE EVOLUTION OF MORPHEEIN BEHAVIOR IN BURKHOLDERIA CENOCEPACIA HMG-COA REDUCTASE THROUGH COMMON ANCESTOR HMGRS
Chad Hicks* (Jeff Watson), Gonzaga University, Dept. of Chemistry and Biochemistry, 502 E Boone Ave, Spokane, WA 99258.
The morpheein model of allosteric regulation is a complex method of regulation in which an enzyme has different, distinct higher order oligomeric forms. Morpheein regulated enzymes can disassociate from their quaternary structure into lower order subunits, undergo tertiary structure changes within these subunits, and reassociate back together into different sized higher order forms. Since this is a new model of protein regulation there are relatively few characterized proteins that have been shown to exhibit morpheein regulation but it is thought that there are many proteins that are morpheeins. Burkholderia cenocepacia HMG CoA-Reductase (BcHMGR) has been found to exhibit this type of regulation while Pseudomonas mevalonii HMGR (PmHMGR) does not exhibit morpheein behavior even though there is a high degree of sequence specificity between BcHMGR and PmHMGR. In studying the evolutionary history of the HMGR, experimentation on three common ancestor HMGRs of PmHMGR and BcHMGR through the use of Size Exclusion Chromatography Multi-Angle Light Scattering (SEC-MALS) and kinetics assays in a range of conditions should help to pinpoint which amino acid mutations led to the presence of morpheein regulation in BcHMGR.