T=1 capsid structures of Sesbania mosaic virus coat protein mutants: determinants of T=3 and T=1 capsid assembly

Journal of Molecular Biology
V SangitaMathur R N Murthy

Abstract

Sesbania mosaic virus particles consist of 180 coat protein subunits of 29kDa organized on a T=3 icosahedral lattice. N-terminal deletion mutants of coat protein that lack 36 (CP-NDelta36) and 65 (CP-NDelta65) residues from the N terminus, when expressed in Escherichia coli, produced similar T=1 capsids of approximate diameter 20nm. In contrast to the wild-type particles, these contain only 60 copies of the truncated protein subunits (T=1). CP-NDelta65 lacks the "beta-annulus" believed to be responsible for the error-free assembly of T=3 particles. Though the CP-NDelta36 mutant has the beta-annulus segment, it does not form a T=3 capsid, presumably because it lacks an arginine-rich motif found close to the amino terminus. Both CP-NDelta36 and CP-NDelta65 T=1 capsids retain many key features of the T=3 quaternary structure. Calcium binding geometries at the coat protein interfaces in these two particles are also nearly identical. When the conserved aspartate residues that coordinate the calcium, D146 and D149 in the CP-NDelta65, were mutated to asparagine (CP-NDelta65-D146N-D149N), the subunits assembled into T=1 particles but failed to bind calcium ions. The structure of this mutant revealed particles that were slightly expande...Continue Reading

References

Mar 1, 1991·Acta Crystallographica. Section A, Foundations of Crystallography·T A JonesM Kjeldgaard
Oct 1, 1990·Acta Crystallographica. Section A, Foundations of Crystallography·L A Tong, M G Rossmann
Jun 20, 1993·Journal of Molecular Biology·R A LaskowskiJ M Thornton
Oct 15, 1995·Structure·M BhuvaneshwariM R Murthy
Apr 1, 1997·Journal of Molecular Graphics & Modelling·R M Esnouf
Oct 3, 1998·Acta Crystallographica. Section D, Biological Crystallography·A T BrüngerG L Warren
Oct 31, 2002·Journal of Structural Biology·Robert W LucasAlexander McPherson
Nov 23, 1978·Nature·S C HarrisonG Bricogne
Jul 3, 1980·Nature·C Abad-ZapateroT Tsukihara

❮ Previous
Next ❯

Citations

Jul 16, 2008·Archives of Virology·Yi-Min WuChan-Shing Lin
May 15, 2009·Proceedings of the National Academy of Sciences of the United States of America·Ranjan V Mannige, Charles L Brooks
Nov 23, 2007·Journal of Virology·Kishore KakaniD'Ann Rochon
Feb 17, 2006·Annual Review of Phytopathology·A L N Rao
Nov 9, 2006·Proceedings of the National Academy of Sciences of the United States of America·Vladimir A Belyi, M Muthukumar
Aug 16, 2011·Journal of Molecular Biology·Stephen W LaneSimon E V Phillips
Feb 17, 2005·Journal of Molecular Biology·Steven B LarsonAlexander McPherson
Oct 20, 2006·Journal of Molecular Biology·Umesh KatpallyThomas J Smith
Apr 10, 2012·Structure·Manfred J Sippl, Markus Wiederstein
Oct 9, 2015·Nature Communications·Ling ZhuDavid I Stuart

❮ Previous
Next ❯

Related Concepts

Related Feeds

Birth Defects

Birth defects encompass structural and functional alterations that occur during embryonic or fetal development and are present since birth. The cause may be genetic, environmental or unknown and can result in physical and/or mental impairment. Here is the latest research on birth defects.