During my summer research I have been tasked with trying to derive the structure of the protein MtrR this protein is an activator for a three gene complex called the MtrCDE. That in turn produces an energy dependent protein by the same name that is a drug efflux pump. This mean that the pump can effectively expel many different antibiotics and other harmful substances from the interior of the cell. Using x-ray crystallography as a final step we can derive the structure down to the resolutions of about 2-3 Å , ( 1 Å is 10^-10 m). At this level you can deduce the three three dimensional structure with the help of the residue sequence. I will be able to figure out which sections of the polypeptide consist of alpha helices, beta sheets, or loop regions. It would also be part of my goal to see how the structure changes when it is bound to the DNA region that it activates. This co-crystallized structure would be expected to be very different than the structure without this DNA complex.
Being able to determine the structure of the pump is a valuable step in the battle against the multi drug resistance (MDR) that is becoming a real issue in today as more and more bacteria are becoming drug resistant. The work that I am doing now falls under that focus of the lab, and I hope to be able to contribute to the goals that this lab has set forth to accomplish. Along with my protein, the lab is also “we are carrying out biochemical and crystallographic studies on the multidrug binding transcription regulators, QacR, BmrR, MtrR, MepR and NfxB that will elucidate their DNA and multidrug binding mechanisms, and hence their modes of regulation of genes involved in MDR” (Brennan 2015)
