Preliminary Analysis of the Adenylate Cyclase (cya) Gene of the Bacterial Predator, Bdellovibrio Bacteriovorus
Micheline Wong
Faculty Advisor: M. O. Martin

     This project explores the possible importance of the cya gene in Bdellovibrio bacteriovorus during its transition from attack to growth phase: Could the cAMP signaling system be part of the predator bacterium's ability to "perceive" the intraperiplasmic space? As a first step, a homologue of the adenylate cyclase gene of Bdellovibrio was isolated by functional complementation of an E. coli mutant using a genomic cosmid bank. The cya-like gene was then subcloned onto a smaller DNA fragment into pUC18 (called pMJW200), and a preliminary DNA restriction map prepared. In our work with this subclone, we discovered that growth inhibition occurred when pMJW200 was present in cya+ E. coli. However, this inhibition disappeared when pMJW200 was transformed into cya+ crp- E. coli strains. This argues that this inhibitor effect of the Bdellovibrio adenylate cyclase in wild type bacteria is mediated through the catabolite regulatory protein (crp), rather than some toxic effect due to increased copy number alone. We hope to complete nucleotide sequence and Southern analysis of the Bdellovibrio cya-like gene, in order to study its organization and compare it to those found by other cAMP researchers. Our eventual goal is the creation of a Bdellovibrio adenylate cyclase mutant, which may allow us to examine the role cAMP plays in periplasmic sensing and prokaryotic predation in general.