Characterization of an Alpha Glucosidase from the Bacterial Predator Bdellovibrio Bacteriovorus

Abstract

An unusual alpha glucosidase gene from the bacterial predator <i style="mso-bidi-font-style:normal">Bdellovibrio bacteriovorus has been isolated and identified and is currently being characterized. Substrate specificity assays using MacConky sugar plates and PNPG chromogens indicate that the enzyme is specific to alpha 1-4 glucosidic bonds, but the length of polymers cleaved by the enzyme is unknown, though it will cleave dimers. RT-PCR analysis indicates that the gene is expressed at the RNA level in both sets of the <i style="mso-bidi-font-style:normal">Bdellovibrio lifecyle. An allelic exchange mutant had been constructed and has been confirmed both genotypically and phenotypically. A lacZ fusion into the gene is being made in order to more easily monitor expression of the gene. Currently, it is believed that <i style="mso-bidi-font-style:normal">Bdellovibrio uses this enzyme to break down stores of polymers, made while in the host cell, while it is out hunting in nutrient poor environments as an emergency energy source. Further work will include characterization of enzyme activity and expression, as well as a transposon search for regulatory genes.