Identification of interaction partners of the dynamin-like protein DynA from Bacillus subtilis.

Membrane dynamics are involved in crucial processes in eukaryotic and prokaryotic cells. Membrane fusion and fission events are often catalyzed by proteins that belong to the dynamin family of large GTPases. It has recently been shown that members of the dynamin superfamily are also present in many bacterial species. Although structural information about full length bacterial dynamin-like proteins is available, their molecular role remains unclear. We have shown previously that DynA, a dynamin-like protein found in the firmicute Bacillus subtilis is able to fuse membranes in vitro. In contrast to other members of the dynamin family this membrane remodeling activity was not dependent on guanosine nucleotides, but required magnesium. DynA assemblies localize in foci that are often enriched at sites of septation and hence a potential role during bacterial cytokinesis was discussed. In order to identify potential interaction partners we constructed a bacterial-two hybrid (B2H) library and screened for DynA interacting proteins. Three potential interaction partner have been identified, YneK, RNaseY (YmdA), and YwpG. Localization of these proteins phenocopies that of DynA, supporting the potential interaction in vivo.