. . . . . . . . . "MSH: In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.,CSP: group of contiguous genes coordinately regulated by a promoter and an operator element; found in prokaryotes." . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .