1X36

T=1 capsid of an amino-terminal deletion mutant of SeMV CP

Summary for 1X36

• Entry DOI: 10.2210/pdb1x36/pdb
• Related: 1SMV 1X33 1X34 1X35
• Descriptor: Coat protein, CALCIUM ION (3 entities in total)
• Functional Keywords: t=1 capsid, n-arm, icosahedral virus, virus
• Biological source: Sesbania mosaic virus
• Total number of polymer chains: 1
• Total formula weight: 25260.64

Authors

Sangita, V.,Satheshkumar, P.S.,Savithri, H.S.,Murthy, M.R. (deposition date: 2005-04-29, release date: 2005-10-18, Last modification date: 2024-11-20)

Primary citation

Sangita, V.,Satheshkumar, P.S.,Savithri, H.S.,Murthy, M.R.
Structure of a mutant T=1 capsid of Sesbania mosaic virus: role of water molecules in capsid architecture and integrity.
Acta Crystallogr.,Sect.D, 61:1406-1412, 2005

PubMed Abstract: Deletion of the N-terminal 31 amino acids from the coat protein (CP) of Sesbania mosaic virus (SeMV) results in the formation of T = 1 capsids. The X-ray crystal structure of CP-NDelta31 mutant capsids reveals that the CP adopts a conformation similar to those of other T = 1 mutants. The 40 N-terminal residues are disordered in CP-NDelta31. The intersubunit hydrogen bonds closely resemble those of the native capsid. The role of water molecules in the SeMV structure has been analyzed for the first time using the present structure. As many as 139 of the 173 waters per subunit make direct contacts with the protein atoms. The water molecules form a robust scaffold around the capsid, stabilize the loops and provide integrity to the subunit. These waters constitute a network connecting diametrically opposite ends of the subunit. Such waters might act as nodes for conveying signals for assembly or disassembly across a large conformational space. Many water-mediated interactions are observed at various interfaces. The twofold interface, which has the smallest number of protein-protein contacts, is primarily held by water-mediated interactions. The present structure illuminates the role of water molecules in the structure and stability of the capsid and points out their possible significance in assembly.

PubMed: 16204894
DOI: 10.1107/S0907444905024030

Experimental method

X-RAY DIFFRACTION (2.7 Å)