VERSATILE DNA-PACKAGING NANOMOTOR OF BACTERIOPHAGE phi29 WITH APPLICATIONS IN NANOBIOTECHNOLOGY

Abstract

Nanobiotechnology entails the use of nanosized materials to build structures that can be applied in both biotechnology and medicine. In one vein of this field of study, scientists seek to mimic the wide variety of nanomachines and macromolecular structures that exist in nature and to replicate them in both structure and function. As a most intriguing example, the bacterial virus phi29 uses a self-contained nanomotor to package its DNA after replication. The 30-nm nanomotor contains 12 copies of a protein (gp10) which together form a 3.6-nm central channel through which the genomic DNA passes into the procapsid during viral assembly and exits during infection. This connector has been recently reengineered and embedded into a lipid bilayer, creating a system with tremendous application for DNA detection and characterization through electrophysiological measurement. A second component of the phi29 bacteriophage is an ATP-binding pRNA that forms a hexameric ring to gear the motor. The pRNA has been utilized to construct nanoparticles of dimers, trimers, hexamers and patterned superstructures via the interaction of two interlocking loops. Such structures constructed via bottom-up assembly have been used in the delivery of drugs, siRNA, ribozymes, and genes to specific cells, both in vitro and in vivo. This review summarizes current studies on the structure, function, and mechanism of the phi29 DNA packaging motor, as well as addresses the applications of these motor components in the field of nanobiotechnology.