Mathematical Biology Seminar

Xiaolin Tang
Department of Physics and Astronomy, University of Utah

Mathematical simulation of early transcription events during VSV infection

Wednesday, October 9, 2013, at 3:05pm
JTB 320


Vesicular stomatitis virus (VSV) is a prototypic negative sense single-stranded RNA virus which shares most of its transcription replication mechanism with deadly human pathogens e.g. Ebola virus. The bullet-shape appearance of the virion results from tightly wound helical turns of the nucleoprotein encapsidated RNA template (N-RNA) around a central cavity. Transcription and replication require polymerase complexes, which include a catalytic subunit L and a template-binding subunit P. Transcription initiates at a promoter site close to the 3' end of the N-RNA template which is located at the tip of the virion. Using super-resolution fluorescence imaging and atomic force microscopy (AFM) on single VSV virions, we have shown that L and P are packaged with uniform density starting from the blunt end of virus. Our finding positions the polymerases at the opposite end of the genome with respect to the only transcriptional promoter. How the polymerase complex finds the promoter region is not well understood. Here we build a model based on the movement of polymerase on the template through Monte Carlo simulation to test several hypotheses. Through this model we have found that one-dimensional diffusion of L along the RNP plays an essential role in transcription initiation and this rate would be a key parameter to be measured in future experiments.