Question

in operon what is present between the promoters and the structural genes

Answer 1

in between promoter and structural gene operator gene is present which controls one or more stuctural genes

Answer 2

Basically, an operon comprises of many structural genes that are put together in a common promoter and supervised with the help of a common operator.

This is basically described as a series of structural genes and regulatory signals that would have an impact on the transcription of the genes.

The regulators would basically comprise of corepressors, activators and repressors.