How do repressor proteins prevent the synthesis of mRNA?
Repressor proteins prevent the synthesis of mRNA by binding to DNA at a specific site near the start of a gene or sequence of genes. The bound repressor protein prevents molecules that are necessary for transcription from binding to initiation sites. RNA polymerase cannot bind to the DNA and the synthesis of RNA cannot occur. The configuration of the repressor protein must match that of the binding site on the DNA. Often another molecule must bind to the repressor to give it the proper configuration. View the animation below, then complete the quiz to test your knowledge of the concept.
