The central dogma of molecular biology involves the production of RNA from genetic DNA which can then be used to make protein. RNA transcription is the process of DNA being coded into RNA. In this process, the DNA sequence in enzymatically copied by RNA polymerase (RNAP) to produce complementary RNA. In eukaryotes there are three types of RNAP while prokaryotes have only one type. RNAP II is responsible for all mRNA synthesis, while RNAP I is responsible for rRNA synthesis and RNAP III synthesizes tRNA in eukaryotes [1]. The process of RNA transcription starts with initiation which is a major control point in the gene expression process of both eukaryotes and prokaryotes [2]. RNA polymerase is a target of many signal transduction pathways and is it also a molecular switch for cell differentiation in development [1]. Our ultimate understanding of gene regulation relies on the ability to understand how RNAP recognizes, binds to, and initiates transcription from the promoter [3].
[1] Cramer, P.; Bushnell, D.A.; Kornberg, R.D. Structural Basis of Transcription: RNA Polymerase II at 2.8 Ångstrom Resolution. Science. 8 June 2001. 292, 1863-1876.
[2] Gnatt, A.L; Cramer, P.; Fu, J.; Bushnell, D.A.; Kornberg, R.D. Structural Basis of Transcription: An RNA Polymerase II Elongation Complex at 3.3 Å Resolution. Science. 8 June 2001. 292, 1876-1882.
[3] Conaway, J.W.; Conaway, R.C. An RNA Polymerase II Transcription Factor Shares Functional Properties with Escherichia coli σ70. Science. 22 June 1990. 248, 1550-1553.