Does the parallel evolution pattern between the replication-segregation proteins and HU have a biological significance?

The bacterial chromosome is a highly compacted nucleoproteic structure, its apparent disordered morphology is difficult to conciliate with newly disco vered mechanisms governing the propagation of genetic information between m other and daughter cells. Recent experiments in bacterial genetics. biochem istry and cytology from a number of laboratories are beginning to unravel h ow at each cell division, DNA replication and segregation proteins interact spatially with specific DNA motifs. to orchestrate replication and movemen t of replication forks and chromosomes. We propose here a method to confirm and perhaps extend these experiments by in silico protein sequence compari sons and phylogeny. This analysis showed a parallel evolution between the h istone-like protein HU and key protein factors involved in DNA replication and chromosome segregation. (C) 2001 Societe francaise de biochimie et biol ogie moleculaire / Editions scientifiques et medicales Elevier SAS.