Kinetic pathway of ATP-induced DNA interactions of ParA2, a protein essential for segregation of Vibrio cholerae chromosome 2

摘要: Vibrio cholerae chromosome 2 (Chr2) requires its own ParABS system for segregation. Without it, V. becomes nonviable and loses pathogenicity. ParA2 of Chr2 is a Walker-type ATPase that the main driver Most our understanding ParA function comes from studying plasmid partition systems. How provides motive force in segregation chromosomes, which are much larger than plasmids, less understood different models have been proposed. Here we analyzed vivo behavior kinetic properties using cell imaging, biochemical biophysical approaches. formed an asymmetric gradient localized dynamically cycle. We found dimers bind ATP undergo slow conformational change to active DNA-binding state, similar P1 ParA. The presence DNA catalyzes allow cooperative binding form higher-order oligomers on DNA. Nucleotide exchange rates were also slow, thus providing control recruitment dynamic localizations. Although highly conserved properties, showed faster overall cycling DNA-rebinding ParAs, suggesting this could be shared features among chromosomal ParAs regulate transport cargo.