FRZCD, A METHYL-ACCEPTING TAXIS PROTEIN FROM MYXOCOCCUS-XANTHUS, SHOWS MODULATED METHYLATION DURING FRUITING BODY FORMATION

The frizzy (frz) genes of Myxococcus xanthus are required to control d irected motility during vegetative growth and fruiting body formation. FrzCD, a protein homologous to the methyl-accepting chemotaxis protei ns from enteric bacteria, is modified by methylation in response to en vironmental conditions. Transfer of cells from rich medium to fruiting medium initially caused rapid demethylation of FrzCD. Subsequently, t he amount of FrzCD increased, but most remained unmethylated. At about the time of mound formation (9 h), most of the FrzCD was converted to methylated forms. Dispersal of developing cells (10 h) in buffer led to the demethylation of FrzCD, whereas concentration of these cells ca used methylation of FrzCD. Some mutants which were unable to form frui ting bodies still modified their FrzCD during incubation under conditi ons of starvation on a surface.