Structural characterization and lipid binding of the virulence factor IivA of Brucella abortus

CARRICA M; CRAIG P; SABIO Y GARCIA J; ROSSETTI O; GOLDBAUM F A; CRAVERO S

Chicago

Conferencia; 59th Annual Brucellosis Research Conference; 2006

We have previously demonstrated that the gene iivA of Brucella abortus is involved in the virulence of these bacteria. This gene encodes for an 11 kDa basic protein of unknown structure and function which is highly conserved in bacteria. The primary sequence analysis predicts two coiled-coil regions encompassing the C and N terminal halves of the molecule. The C terminal coiled-coil has a higher score than the N terminal one. IivA-self associates as a trimer by its terminal region as shown by light scattering and cross-linking experiments. In this study, we carried out the characterization of the secondary structure of IivA protein and its behavior in different conditions. Besides, we evaluated the IivA-interaction with phospholipid and its in vitro membrane- fusion activity at neutral and acidic pH. These data could contribute to understand the molecular bases of IivA function and the intimate mechanisms of Brucella virulence.