In the eukaryotes, the transmit RNA genes exist as multiple copies and are transcribed by RNA polymerase III or RNA Pol III. As in prokaryotes, various tRNAs may be transcribed together to yield a one pre- transfer RNA molecule that is then processed to release the mature transfer RNAs.  The  promoters  of  eukaryotic  transfer RNA  genes  are generally in which the transcriptional  control components are situated downstream  example for on the 3'  side of the transcriptional  start site (at position + 1). In reality they lie within the gene itself. Two such components have been recognized, called the A box and B box. The Transcription of the transmit RNA genes through RNA Pol III requires transcription factor IIIC (TFIIIC) as well as TFIIIB. The TFIIIC binds to the A and B boxes whilst TFIIIB binds upstream of the A box. TFIIIB holds three subunits, one of that is TBP (TATA binding protein), the polypeptide needed by all three eukaryotic RNA polymerases.