TrxA in A. aceti

Brittney Heard, Julie Francois, Susan Hockings, T. J. Kappock, Chemistry Department Washington University, St. Louis, MO

In normal bacteria (bugs), as the external pH drops to an acetic level, bacteria die. However, in acid resistant bacteria, as the external pH drops, bacteria survive and continue to function properly. There are two types of acid resistant bacteria - neutral and variable. In neutral acid resistant bacteria, as the external pH drops, the internal pH remains the same (neutral). In variable acid resistant bacteria, as the external pH drops, the internal pH drops also. One particular example of a variable acid resisting bacterium is Acetobacter aceti (A. aceti). A. aceti is currently being researched to understand the biochemical guidelines for life at low pH.

In order to attain these biochemical guidelines, the proteins of A. aceti must first be studied and their functions determined. For this particular experiment, thioredoxin (TrxA) was the protein of interest. A. aceti TrxA, previously cloned into a protein expression vector, was expressed in E. coli BL21(DE3) cells. Strong expression of a soluble 15 kDa protein was noted. Attempts to purify recombinant A. aceti TrxA are in progress.