Chromosome segregation in Escherichia coli involves DNA binding by the MinC-MinD complex

Abstract

The Escherichia coli Min system, composed of the proteins MinC, MinD, and MinE, is crucial for directing septum formation at mid-cell. MinD has also been implicated in chromosome segregation due to its non-sequence-specific DNA binding ability. Here, we demonstrate that the MinCD complex, rather than MinD alone, is the primary driver of Min-mediated chromosome segregation and that MinE regulates the transient nature of this interaction. We further reveal a critical function for the linker connecting MinC’s N- and C-terminal domains in both DNA binding and FtsZ polymerization inhibition. E. coli strains expressing MinC linker variants from the native locus exhibit chromosome segregation defects. The defects are more pronounced in strains where the nucleoid-associated protein HU is endogenously tagged with GFP. These findings reinforce the involvement of the Min system in chromosome segregation in E. coli and highlight a previously unrecognized role for the MinC linker.