Berlin 2012 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 16: Molecular Motors

BP 16.7: Vortrag

Mittwoch, 28. März 2012, 17:00–17:15, H 1028

Transcriptional proofreading in dense RNA Polymerase traffic — •Mamata Sahoo and Stefan Klumpp — Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany

The correction of errors during transcription involves the diffusive backward translocation (backtracking) of RNA polymerases (RNAPs) on the DNA. A trailing RNAP on the same template can interfere with backtracking as it progressively restricts the space that is available for backward translocation and thereby ratchets the backtracked RNAP forward. We analyze the resulting negative impact on proofreading theoretically using a lattice model of transcription introduced earlier [1]. Our detail analysis indicates that the efficiency of error correction is essentially determined by the rate for the initial backtracking step, while a high transcript cleavage rate ensures that the correction mechanism remains efficient at high transcription rates [2]. Our analysis can also be applied to cases with transcription-translation coupling where the leading ribosome on the transcript assumes the role of the trailing RNAP.

[1] S. Klumpp and T. Hwa, PNAS 105, 18159 (2008).

[2] M. Sahoo and S. Klumpp, Euro. Phys. Lett. (in press) (2011).