Talk abstracts

Talk on Friday 09:30-09:50pm submitted by Feng Xiao

Engineering of an active artificial bacteriophage phi29 pRNA

Feng Xiao (Department of Biomedical Engineering, University of Cincinnati), Nick Snead (Weldon School of Biomedical Engineering, Purdue University), Hui Zhang (Department of Biomedical Engineering, University of Cincinnati), Peixuan Guo (Department of Biomedical Engineering, University of Cincinnati)

Abstract:
Bacterial virus phi29 DNA-packaging motor includes a connector geared by six pRNAs (packaging RNA) and a DNA packaging enzyme gp16. phi29 pRNA, with a minimum size of 117 bases, is another essential component of the motor. It contains two functional domains: the central procapsid binding domain and the 5'/3' ends paired the DNA translocation domain. pRNA forms dimers, trimers and hexamers via a hand-in-hand interaction through the base-pairing of two interlocking left- and right-hand loops. We designed a new artificial RNA molecule Y, bearing a sequence completely different from that of wild-type phi29 pRNA, can fold into the same secondary structure as that of pRNA. This RNA bound to the procapsid with an affinity similar to the wild type phi29 pRNA and was biologically active in the assembly of infectious phi29 virion. However, if 2-3 nucleotides on the right/left loops of artificial RNA Y were mutated, it resulted in the loss of activity in phi29 virion assembly. Further inverstigation of the single molecule photobleaching study on the procapsid/Cy3-artificial RNA Y complex revealed a good photobleaching pattern corresponding to the model of ring with six copies of pRNA. The principle for the design and construction of an artificial pRNA biologically active during a viral DNA packaging motor will be presented.

Keywords: Bacteriophage phi29, pRNA