10.4 Mutations identify the operator and the regulator gene Figure 10.8 Operator mutations are constitutive because the operator is unable to bind 血收自事卡只 ctive repressor cannot bind to o mutant operator repressor protein; this allows rna polymerase to have 入 M unrestrained access to the promoter. The Oc o operator mutations are ciS- O peron is transcribed acting, because they and translated affect only the contiguous set of ↓ structural genes 请莘大Figure 10.8 Operator mutations are constitutive because the operator is unable to bind repressor protein; this allows RNA polymerase to have unrestrained access to the promoter. The Oc mutations are cis￾acting, because they affect only the contiguous set of structural genes. 10.4 Mutations identify the operator and the regulator gene