CAP in LAC operon is

In prokaryotes, the genes involved in a metabolic pathway are often present in a linear array called an operon, for example, the lac operonThe structural gene for b-galactosidase (lacZ) is clustered with the genes responsible for the permeation of lactose into the cell (lacY) and for thiogalactoside transacetylase (lacA). The structural genes for these three enzymes (lacZ, lacY, lacA), along with the lac promoter and lac operator (a regulatory region), are physically associated to constitute the lac operonImmediately upstream of the lac operon promoter is the binding site (CRE) for the cAMP binding protein, CAP, the positive regulator of lac operon transcriptionRef: Harper 29e, page: 430