Nollmann

Our interests
We are interested primarily on the mechanisms of molecular motors that transport DNA in and between bacteria.These motors use the enerygy of ATP hydrolysis to processively translocate DNA between cellular compartments or within different cells, and belong to the large and diverse AAA+ family of enzymes. AAA+ motors form multimeric  rings in which ATP hydrolysis and mechanical work are closely coupled. In general, we are interested in understanding the larger network of genetic interactions affecting the process of DNA transport in vivo. In particular, we want to understand the general mechanisms governing translocation directionality, transduction of energy into movement, and complex assembly. We are currently investigating DNA transport in two model systems: chromosome segregation by FtsK during cell division in Escherichia coli and  by SpoIIIE  during  sporulation in Bacillus subtilis. Despite being mechanistically similar, these two DNA transport systems have been adapted for different biological processes (chromosome dimer resolution and sporulation) and will probably display different sets of genetic interactions. To tackle these problems, we are developing and using state-of-the-art single-molecule and microscopy techniques in vitro, to benefit from the unique detailed mechanistic insights obtained with reconstituted systems, and in vivo to fit our findings into the larger picture and find interaction partners that might be implicated in the process of DNA transfer. Our integrative approach involves the use of  single-molecule manipulation (magnetic and optical tweezers) and  imaging methods, such as Atomic Force Microscopy (with P-E Milhet) or super-resolution microscopy (with E Margeat), genetic and cell biology methodologies. We work closely together with French and International collaborators including Francois Cornet (CNRS-Toulouse, http://www-lmgm.biotoul.fr/equipes/grpcornet), Kit Pogliano (UCSD, http://www.biology.ucsd.edu/labs/pogliano/) and Carlos Bustamante (UC Berkeley, http://alice.berkeley.edu/). We have postdoc and PhD positions available so don't hesitate in contacting me if you are interested.