Publication details
The three-dimensional structure of ryegrass mottle virus at 2.9 angstrom resolution
| Authors | |
|---|---|
| Year of publication | 2007 |
| Type | Article in Periodical |
| Magazine / Source | Virology |
| MU Faculty or unit | |
| Citation | |
| Doi | http://dx.doi.org/10.1016/j.virol.2007.07.028 |
| Field | Microbiology, virology |
| Keywords | Ryegrass mottle virus; sobemovirus; virus structure; virus assembly |
| Description | The cystal structure of the sobemovirus Ryegrass mottle virus (RGMoV) has been determined at 2.9 angstrom resolution. The coat protein has a canonical jellyroll beta-sandwich fold. In comparison to other sobemoviruses the RGMoV coat protein is missing several residues in two of the loop regions. The first loop contributes to contacts between subunits around the quasi-threefold symmetry axis. The altered contact interface results in tilting of the subunits towards the quasi-threefold axis. The assembly of the T = 3 capsid of sobemoviruses is controlled by the N-termini of C subunits forming a so-called beta-annulus. The other loop that is smaller in the RGMoV structure contains a helix that participates in stabilization of the beta-annulus in other sobernoviruses. The loss of interaction between the RGMoV loop and the beta-annulus has been compensated for by additional interactions between the N-terminal arms. As a consequence of these differences, the diameter of the RGMoV particle is 8 A smaller than that of the other sobemoviruses. The interactions of coat proteins in sobemovirus capsids involve calciurn ions. Depletion of calcium ions results in particle swelling, which is considered a first step in disassembly. We could not identify any density for metal ions in the proximity of the conserved residues normally involved in calcium binding, but the RGMoV structure does not show any signs of swelling. A likely reason is the low pH (3.0) of the crystallization buffer in which the groups interacting with the calcium ions are not charged. (c) 2007 Elsevier Inc. All rights reserved. |