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Updated: Aug 11, 2026

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
Published on: March 13, 2019
Hexameric molecular motors: P4 packaging ATPase unravels the mechanism
D E Kainov1, R Tuma, E J Mancini
1Institute of Biotechnology and Department of Biological and Environmental Sciences, University of Helsinki, Viikki Biocenter, P. O. Box 65, Helsinki, 00014, Finland. dkainov@hotmail.com
Abstract:
Genome packaging into an empty capsid is an essential step in the assembly of many complex viruses. In double-stranded RNA (dsRNA) bacteriophages of the Cystoviridae family this step is performed by a hexameric helicase P4 which is one of the simplest packaging motors found in nature. Biochemical and structural studies of P4 proteins have led to a surprising finding that these proteins bear mechanistic and structural similarities to a variety of the pervasive RecA/F1-ATPase-like motors that are involved in diverse biological functions. This review describes the role of P4 proteins in assembly, transcription and replication of dsRNA bacteriophages as it has emerged over the past decade while focusing on the most recent structural studies. The P4 mechanism is compared with the models proposed for the related hexameric motors.
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