In eukaryotic cells, many membrane fusion and fission events are controlled by large GTPases of the dynamin protein superfamily. The members of this family use GTP hydrolysis to cause membrane curvature and constriction, for example, during vesicle budding. The recent discovery of bacterial dynamin-like proteins (BDLPs) that bind and remodel membranes has brought to light the diverse roles these proteins play in regulating membrane dynamics across the domains of life (Low et al, 2010). We have identified a family of BDLPs in diverse strains of H. pylori. This family of proteins is most closely related to proteins from enterotoxigenic Escherichia coli that have been implicated in bacterial membrane vesicle formation and toxin delivery (Michie et al, 2014).

Most BDLP genes are found as a pair, each one encoding a full-length dynamin homolog. In H. pylori, one of these genes is split into two (dfmC and dfmB), with a predicted membrane-spanning helix adjacent to the split—at the N-terminus of DfmB. The gene arrangement and presence of a predicted transmembrane helix implies that these proteins may act as a hetero-complex involved in membrane remodeling. Our hypothesis is that DfmCBA are part of membrane vesicle production or a secretory pathway important for infection. Here, we will present our current results of a bioinformatic analysis of these previously uncharacterised proteins, and experimental studies of their expression, molecular interactions, sub-cellular localisation and role in H. pylori.

Low, H., Lowe, J. (2010) Dynamin architecture —from monomer to polymer. Current Opinion in Structural Biology, 20: 791–798.

Michie, K.A., Boysen, A., Low, H.H., Møller-Jensen, J., Lowe, J. (2014). LeoA, B and C from Enterotoxigenic Escherichia coli (ETEC) Are Bacterial Dynamins. PLoS ONE, 9(9): e107211.