Repressors are proteins that inhibit gene expression, They usually have DNA or RNA binding site which enables them to binde to the operator or associated silencers. Allosteric domain is the site for the binding of other molecules, such as corepressors and inducers that regulate repressor's activity.
Reasoning - First to point out All (Living) Things are (Made) Up of (Cells). Second Cellular function or cells function have the same chemical makeup that perform a common function.
