Abstracts » Biological sciences

RNA polymerase slides home: pause and termination site recognition

Article Abstract:

RNA polymerase (RNAP) have been determined to perform the function of facilitating chain elongation as well as recognizing pause signals and termination sites during the process. A sliding-clamp model of the transcription complex has been proposed to explain the mechanism by which RNAP performs such functions. In the model, RNAP encircles duplex DNA ahead of the active site then slides backwards to increase the stability of a constant-sized RNA:DNA hybrid of about 8 bp.

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Discontinuous movements of DNA and RNA in RNA polymerase accompany formation of a paused transcription complex

Article Abstract:

Transcriptional pausing could be a result of discontinuous movements of RNA polymerase along DNA and RNA chains. Changes in 3'-proximal or a downward DNA affect discontinuity of DNA and RNA movements accompanying RNA polymerase and pause RNA hairpin restricts the new downward DNA in the paused complex. It is possible that the discontinuous movements regulate both termination and antitermination because stopping the discontinuous movement causes antitermination.

Genetic regulation

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Inhibition of RNA polymerase by streptolydigin: No cycling allowed

Article Abstract:

A structural basis for inhibition of bacterial RNA polymerase by the antibiotic streptolydigin is described. Streptolydigin prevents the distortion of a bridge (alpha) helix postulated to occur at the time of nucleotide addition cycle of RNA polymerase or block a small movement of the bridge helix that helps load nucleotide triphosphates into active site.

Science & research, Biological Product (except Diagnostic) Manufacturing, Nucleic Acid Derivatives, Nucleotides, Genetic research, Nucleotide sequencing

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