Abstract
Chromosome segregation during sporulation in Bacillus subtilis involves the anchoring of sister chromosomes to opposite ends of the cell. Anchoring is mediated by RacA, which acts as a bridge between a centromere-like element in the vicinity of the origin of replication and the cell pole. To define this element we mapped RacA binding sites by performing chromatin immunoprecipitation in conjunction with gene microarray analysis. RacA preferentially bound to 25 regions spread over 612 kb across the origin portion of the chromosome. Computational and biochemical analysis identified a GC-rich, inverted 14 bp repeat as the recognition sequence. Experiments with single molecules of DNA demonstrated that RacA can condense nonspecific DNA dramatically against appreciable forces to form a highly stable protein-DNA complex. We propose that interactions between DNA bound RacA molecules cause the centromere-like element to fold up into a higher order complex that fastens the chromosome to the cell pole.
| Original language | English |
|---|---|
| Pages (from-to) | 773-782 |
| Number of pages | 10 |
| Journal | Molecular Cell |
| Volume | 17 |
| Issue number | 6 |
| DOIs | |
| State | Published - 18 Mar 2005 |
Bibliographical note
Funding Information:S.B.-Y. was a Human Frontier Science Program (HFSP) postdoctoral scholar at the laboratory of R.L. and is currently supported by the Career Development Award (CDA) of the HFSP and the Israel Science Foundation (ISF grant 1401/04). The work at the laboratory of R.L. (Harvard) was supported by National Institutes of Health grant GM18568. The work at the laboratory of J.F.M. (University of Illinois at Chicago) was supported in part by National Science Foundation grants DMR-0203963 and MCB-0240998 and by a Focused Giving grant from Johnson and Johnson Corporation. J.S.L. (Harvard) was supported by NSF grant DMS-0244638.