Due to the circular nature of many bacterial chromosomes, an odd number of crossing-over events that occur during homologous recombination lead to chromosome dimer formation. These dimers need to be resolved before successful cell division can occur. Bacteria undergo this resolution of chromosome dimers via site-specific recombination. In Escherichia coli, the action of FtsK, XerC and XerD during site-specific recombination facilitates two strand exchange reactions which resolve chromosome dimers thus allowing cell division to proceed as normal. FtsK interacts with specific sequences that orient the protein toward “dif” sites, positioning the chromosome so XerC/D can undertake the recombination reaction. FtsK also has a role during cell division in which it pumps DNA at an extraordinary rate to hasten cytokinesis and chromosome segregation. The N-terminus of FtsK is primarily responsible for localisation of the protein during cell division and assembly of cell-division machinery, whilst the C-terminus forms the motor domain. Within the motor domain, there exists three subdomains, called  α, β and γ. α and β form a hexameric ring with a 32Ådiameter channel (large enough for double-stranded DNA) whilst γ binds to specific sequences known as KOPS (FtsK Orienting Polar Sequences), thus orienting the protein toward dif. The work conducted herein, seeks to clarify structural information of FtsK by creating several mutations and variants and testing their recombination activity in vitro. There will also be a strong focus on isolation of FtsK, XerC and XerD from E.coli, Pseudomonas aeruginosa and Acinetobacter baylyi. Biochemical and crystallographic assays will be used to elucidate previously unknown structural information on these proteins as well as functional properties that, at least in A.baylyi, are currently unknown. By combining proteins from all three systems in an in vitro recombination assay, we hope to further validate the conserved nature of this site-specific recombination system in bacteria.