Catalyses DNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time. Can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. See also EC 2.7.7.19 (polynucleotide adenylyltransferase) and EC 2.7.7.48 (RNA-directed RNA polymerase).
rna polymerase ii, pol ii, t7 rna polymerase, rna polymerase i, pol iii, rna polymerase iii, pol i, rnapii, rnap ii, dna-dependent rna polymerase, more
Catalyses DNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time. Can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. See also EC 2.7.7.19 (polynucleotide adenylyltransferase) and EC 2.7.7.48 (RNA-directed RNA polymerase).
multi-subunit DNA-dependent RNA polymerases synthesize RNA molecules thousands of nucleotides long. The reiterative reaction of nucleotide condensation occurs at rates of tens of nucleotides per second, invariably linked to the translocation of the enzyme along the DNA template, or threading of the DNA and the nascent RNA molecule through the enzyme. Reiteration of the nucleotide addition/translocation cycle without dissociation from the DNA and RNA requires both isomorphic and metamorphic conformational flexibility of a magnitude substantial enough to accommodate the requisite molecular motions
RNAP adds nucleotides to the 3'-end of the growing RNA and translocates reiteratively, in single nucleotide steps. Translocation mechanism models, concerning conformational changes, allosteric effects and isomerization, and model evaluation, overview
the enzyme active site is located on the back wall of the channel, where an essential Mg2+ ion is chelated by three Asp of the absolutely conserved NADFDGD motif in the A' subunit
multi-subunit DNA-dependent RNA polymerases synthesize RNA molecules thousands of nucleotides long. The reiterative reaction of nucleotide condensation occurs at rates of tens of nucleotides per second, invariably linked to the translocation of the enzyme along the DNA template, or threading of the DNA and the nascent RNA molecule through the enzyme. Reiteration of the nucleotide addition/translocation cycle without dissociation from the DNA and RNA requires both isomorphic and metamorphic conformational flexibility of a magnitude substantial enough to accommodate the requisite molecular motions
the enzyme active site is located on the back wall of the channel, where an essential Mg2+ ion is chelated by three Asp of the absolutely conserved NADFDGD motif in the A' subunit
reverse translocation, i.e. backtracking, by a distance of one or more nucleotides disrupts the configuration of the catalytic center, leading to a temporary, spontaneously resolved, halt of the RNAP, called pausing, or to a transition into an irreversible arrested state. The latter can be restored to functionality by the endonucleolytic cleavage of the RNA or by pushing the backtracked complex from behind. Non-backtracked paused complexes are also described for bacterial RNAPs, where addition of the incoming NTP is hindered owing to isomerization of the active site into an inactive conformation
structure and modeling of the multi-subunit enzyme complex, RNAP subunits can be divided into three groups concerned with catalysis, assembly of the catalytic subunits and auxiliary functions, overview. The large A and B subunits are split into two polypeptides, A'/A'' and B''/B' according to size, they harbour the binding sites for substrate NTPs, duplex DNA template and a 9 bp DNA-RNA hybrid, and provide the catalytic centre, including three catalytic aspartic acid residues and two Mg2+ ions
secondary structure and organization of multi-subunit DNA-dependent RNA polymerases, overview. The Rpb8/G RNA polymerase subunit is restricted to eukaryotes and Crenarchaea. The enzyme lacks the G subunit
structure analysis, overview, the enzyme contains a subunit Rpo13 located at a groove between the H subunit and the clamp head domain of the A' subunit, model ing including the A' subunit jaw and clamp head domains and RpoG and Rpo13, overview
The X-ray crystal structure of RNA polymerase from Archaea
Nature
451
851-854
2008
Saccharolobus solfataricus (Q980R2 and P58192 and Q980R1 and P95989 and Q980A3 and Q9UXD9 and Q980L5 and Q980Q9 and Q97ZJ9 and Q980K0 and Q980Z8 and Q97ZX7 and Q980B8), Saccharolobus solfataricus, Saccharolobus solfataricus P2 (Q980R2 and P58192 and Q980R1 and P95989 and Q980A3 and Q9UXD9 and Q980L5 and Q980Q9 and Q97ZJ9 and Q980K0 and Q980Z8 and Q97ZX7 and Q980B8)