A NEGATIVE REGULATOR LINKING CHROMOSOME SEGREGATION TO DEVELOPMENTAL TRANSCRIPTION IN BACILLUS-SUBTILIS

The Spo0JA and Spo0JB proteins of Bacillus subtilis are similar to the ParA and ParB plasmid-partitioning proteins, respectively, and mutati on of spo0JB prevents the expression of stage II genes of sporulation. This phenotype is a consequence of Spo0JA activity in the absence of Spo0JB, and its basis was unknown. In the studies reported here, Spo0J A was found specifically to dissociate transcription initiation comple xes formed in vitro by the phosphorylated sporulation transcription fa ctor Spo0A and RNA polymerase with the spollG promoter. This repressor -like activity is likely to be the basis for preventing the onset of d ifferentiation in vivo. Spo0JB is known to neutralize Spo0JA activity in vivo and also to interact with a mitotic-like apparatus responsible for chromosome partitioning. These data suggest that Spo0JA and Spo0J B form a regulatory link between chromosome partition and development gene expression.