Study of the functional and structural diversity of a nucleoid-associated protein family

Abstract

Studies on proteins that organize the genetic material and, consequently, affect gene expression, are still limited to just a few bacteria. In the case of the H-NS protein, which bridges segments of the chromosome, the studies focus on the gamma-proteobacteria Escherichia coli and Salmonella enterica. In alpha- and beta-proteobacteria, H-NS proteins are naturally shortened in several regions when compared to E. coli and S. enterica homologues. This shortening could affect the ability of the proteins to oligomerize, bind to DNA and respond to environmental conditions. In the present study, we aimed to characterize the H-NS protein from the alpha-proteobacterium Bartonella henselae, which has a more divergent predicted structure compared to H-NS from E. coli and S. enterica, amongst the alpha- and beta- proteobacteria evaluated. Chimeras combining part of B. henselae H-NS with part of E. coli H-NS will be constructed and analyzed, providing us with data about the structural and functional similarity amongst these members of the H-NS family. A biochemical characterization of H-NS from B. henselae, including the evaluation of the oligomerization and DNA-binding properties, will also be performed. (AU)