Evidence for an electrostatic mechanism of force generation by the bacteriophage T4 DNA packaging motor.

Published

Journal Article

How viral packaging motors generate enormous forces to translocate DNA into viral capsids remains unknown. Recent structural studies of the bacteriophage T4 packaging motor have led to a proposed mechanism wherein the gp17 motor protein translocates DNA by transitioning between extended and compact states, orchestrated by electrostatic interactions between complimentarily charged residues across the interface between the N- and C-terminal subdomains. Here we show that site-directed alterations in these residues cause force dependent impairments of motor function including lower translocation velocity, lower stall force and higher frequency of pauses and slips. We further show that the measured impairments correlate with computed changes in free-energy differences between the two states. These findings support the proposed structural mechanism and further suggest an energy landscape model of motor activity that couples the free-energy profile of motor conformational states with that of the ATP hydrolysis cycle.

Full Text

Duke Authors

Cited Authors

  • Migliori, AD; Keller, N; Alam, TI; Mahalingam, M; Rao, VB; Arya, G; Smith, DE

Published Date

  • June 17, 2014

Published In

Volume / Issue

  • 5 /

Start / End Page

  • 4173 -

PubMed ID

  • 24937091

Pubmed Central ID

  • 24937091

Electronic International Standard Serial Number (EISSN)

  • 2041-1723

International Standard Serial Number (ISSN)

  • 2041-1723

Digital Object Identifier (DOI)

  • 10.1038/ncomms5173

Language

  • eng