ABSTRACT
Ribonucleic acid (RNA) polymerase binding to the promoter requires the formation of a transcription initiation complex involving several general transcription factors that assemble in a strict order. In marked contrast to prokaryotic genes where proteins are encoded by a continuous sequence of triplet codons, the vast majority of protein-coding genes in eukaryotes are discontinuous. Elongation continues until transcription comes to a halt at varying distances downstream of the gene, releasing the primary RNA transcript, pre-messangerRNA (mRNA). The primary transcript is a pre-mRNA molecule which must be processed to yield mature mRNA ready for translation. Unlike the situation in prokaryotes, the primary transcript from a eukaryotic protein-coding gene is a precursor molecule, pre-mRNA, that needs extensive RNA processing in order to yield mature mRNA ready for translation. For a high rate of transcription, other transcription factors are required which bind to additional sequence elements and interact with this initiation complex.
