Methods for structural and functional analysis of an RNA hexamer of bacterial virus phi29 DNA packaging motor

During multiplication and maturation, the lengthy genomic DNA of dsDNA viruses is translocated with remarkable velocity into a limited space within the procapsid and packaged to crystalline density. A viral DNA-packaging motor accomplishes this energy consuming motion task. An RNA molecule of bacterial virus phi29 has been found to be a vital component of the DNA-packaging motor. Six pRNAs form a hexagonal complex to gear the DNA translocating machine using a mechanism similar to the driving of a bolt with a hex nut. Sequential action of six RNA molecules to drive the motor is similar to the consecutive firing of six cylinders of a car engine. This article reviews the structure of pRNA to demonstrate that its structure plays a vital role in its function, and focuses on methods and unique approaches that lead to the elucidation of pRNA structure.