Rac and Rab GTPases dual effector Nischarin regulates vesicle maturation to facilitate survival of intracellular bacteria.

The intracellular pathogenic bacterium Salmonella enterica serovar typhimurium (Salmonella) relies on acidification of the Salmonella-containing vacuole (SCV) for survival inside host cells. The transport and fusion of membrane-bound compartments in a cell is regulated by small GTPases, including Rac and members of the Rab GTPase family, and their effector proteins. However, the role of these components in survival of intracellular pathogens is not completely understood.

A conserved domain in prokaryotic bifunctional FAD synthetases can potentially catalyze nucleotide transfer.

Biosynthesis of flavin adenine dinucleotides in most prokaryotes is catalyzed by a family of bifunctional flavin adenine dinucleotide (FAD) synthetases. These enzymes carry out the dual functions of phosphorylation of flavin mononucleotide (FMN) and its subsequent adenylylation to generate FAD. Using various sequence analysis methods, a new domain has been identified in the N-terminal region that is well conserved in all the bacterial FAD synthetases.