Initiation of transcription by RNA polymerase II requires the activities of more than 70 polypeptides. The protein that coordinates these activities is transcription factor IID (TFIID), which binds to the core promoter to position the polymerase properly, serves as the scaffold for assembly of the remainder of the transcription complex, and acts as a channel for regulatory signals. TFIID is composed of the TATA-binding protein (TBP) and a group of evolutionarily conserved proteins known as TB

Protein tags are protein or peptide sequences located either on the C- or N- terminal of the target protein, which facilitates one or several of the following characteristics: solubility, detection, purification, localization and expression. Maltose binding protein(MBP) is the 370 amino acid product of the E.coli mal E gene. MBP is a useful affinity tag that can increase the expression level and solubility of the resulting tagged protein. The MBP tag also promotes proper folding of the attach

Somatostatin is a tetradecapeptide that is widely distributed in the body and is one of five receptor subtypes termed SSTr1-. These receptors function in the regulation of numerous phsiological processes such as the secretion of insulin, glucagon and growth hormone as wel as cell growth induced by neuronal excitation in both the central and peripheral nervous systems. Somatostatin receptos are activated via sonatostatin secreted by nerve and endocrine cells. Somatostatin Receptor 2 (SSR2),