IDENTIFICATION OF A NOVEL ADENYLATE-CYCLASE IN THE RUMINAL ANAEROBE, PREVOTELLA-RUMINICOLA D31D

Our previous evaluation of ruminal and other anaerobic bacteria showed only Prevotella ruminicola D31d produced detectable concentrations of cyclic AMP. In order to investigate the synthesis of this important m etabolic regulator, the gene for adenylate cyclase (cya), which produc es cyclic AMP, was cloned and expressed in a CyaA mutant of Escherichi a coli. The cloned P. ruminicola D31d gene was able to complement the cyaA mutation and permitted fermentation of lactose on MacConkey Lacto se agar plates. Analysis of the DNA sequence of the 2.5-kilobase pair insert revealed an open reading frame encoding for a 67-kDa protein. T his protein was novel in that no amino acid similarity was observed wi th other procaryotic or eucaryotic adenylate cyclases in the GenBank d atabase. Production of cyclic AMP in the E. coli clone was confirmed w ith a radioimmunoassay technique. This is the first example of an aden ylate cyclase gene identified from an anaerobic bacterium. (C) 1998 Fe deration of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.