Final answer:
The type of regulator that a polypeptide can be is typically an allosteric regulator, which is a form of post-translational regulation modifying the protein's function or location. Gene regulation also occurs at the translation level, both globally and specifically, and at the transcription level, involving structural and regulatory genes.
Step-by-step explanation:
Types of Regulation in Gene Expression
The specific type of regulator a polypeptide can be is typically an allosteric regulator. Allosteric regulators can bind to proteins at a location different from the active site and cause a change in the protein's function. This is a form of post-translational regulation, which controls gene expression by modifying proteins after they have been synthesized. For instance, the activity and stability of enzymes can be influenced by adding or removing chemical groups, such as phosphates, which can alter the enzyme's function or location within the cell.
Translation regulation can be either global or specific. Global regulation impacts the synthesis of many polypeptides by affecting the activity of eukaryotic initiation factors, while specific regulation targets the translation of particular mRNAs through binding of regulatory proteins or other molecules to sequences or regions on the mRNA.
Transcription regulation is another common form where gene expression is controlled at the level of transcription initiation. Structural and regulatory genes play distinct roles here, with structural genes providing the blueprint for proteins and RNAs, while regulatory genes control when and how much of these gene products are made.