Abstract The CcpA protein has been identified as a key regulator of carbon metabolism in Bacillus subtilis. CcpA is a DNA binding protein in the LacI/GalR transcriptional repressor family, and genes which respond to CcpA contain icommon cis-acting target sequences (Ccp boxes). A number of pathways involved in carbon source utilization are repressed by CcpA, while at least one gene which is involved in excretion of excess carbon is activated by CcpA. Genes repressed by CcpA generally contain Ccp boxes within or downstream of the promoter, while ackA, which is activated by CcpA, contains Ccp boxes upstream of the promoter. It therefore appears that CcpA acts globally to direct carbon flow in B. subtilis.