Virus capsid expansion driven by the capture of mobile surface loops.
Lee, K.K., Gan, L., Tsuruta, H., Moyer, C., Conway, J.F., Duda, R.L., Hendrix, R.W., Steven, A.C., Johnson, J.E.(2008) Structure 16: 1491-1502
- PubMed: 18940605
- DOI: https://doi.org/10.1016/j.str.2008.06.014
- Primary Citation of Related Structures:
3DDX - PubMed Abstract:
The capsids of tailed-DNA bacteriophages first assemble as procapsids, which mature by converting into a new form that is strong enough to contain a densely packed viral chromosome. We demonstrate that the intersubunit crosslinking that occurs during maturation of HK97 capsids actually promotes the structural transformation. Small-angle X-ray scattering and crosslinking assays reveal that a shift in the crosslink pattern accompanies conversion of a semimature particle, Expansion Intermediate-I/II, to a more mature state, Balloon. This transition occurs in a switch-like fashion. We find that crosslink formation shifts the global conformational balance to favor the balloon state. A pseudoatomic model of EI-I/II derived from cryo-EM provides insight into the relationship between crosslink formation and conformational switching.
Organizational Affiliation:
Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.