This general class were present in the ur-actinobacterium, giving rise to the possibility of subtle control of sigma factor activity by signals that might include morphological checkpoints (as in the case of the spoIIAA/spoIIAB genes of B. subtilis; PiggotHilbert, 2004) or stress (as in the case of sigB of B. subtilis; Price, 2000). Indeed, BldG influences the activity of the stress-responsive sig