2BT8

Structure of the C-terminal receptor-binding domain of avian reovirus fibre sigmaC, space group P6322.

Summary for 2BT8

• Entry DOI: 10.2210/pdb2bt8/pdb
• Related: 2BSF 2BT7
• Descriptor: SIGMA C (2 entities in total)
• Functional Keywords: orthoreovirus, triple beta-spiral, beta-barrel, viral protein
• Biological source: AVIAN ORTHOREOVIRUS
• Total number of polymer chains: 1
• Total formula weight: 18324.34

Authors

Guardado Calvo, P.,Fox, G.C.,Hermo Parrado, X.L.,Llamas-Saiz, A.L.,van Raaij, M.J. (deposition date: 2005-05-26, release date: 2005-11-03, Last modification date: 2024-05-08)

Primary citation

Guardado Calvo, P.,Fox, G.C.,Hermo Parrado, X.L.,Llamas-Saiz, A.L.,Costas, C.,Martinez-Costas, J.,Benavente, J.,van Raaij, M.J.
Structure of the Carboxy-Terminal Receptor-Binding Domain of Avian Reovirus Fibre Sigmac
J.Mol.Biol., 354:137-, 2005

PubMed Abstract: Avian reovirus fibre, a homo-trimer of the sigmaC protein, is responsible for primary host cell attachment. The protein expressed in bacteria forms elongated fibres comprised of a carboxy-terminal globular head domain and a slender shaft, and partial proteolysis yielded a carboxy-terminal protease-stable domain that was amenable to crystallisation. Here, we show that this fragment retains receptor-binding capability and report its structure, solved using two-wavelength anomalous diffraction and refined using data collected from three different crystal forms at 2.1 angstroms, 2.35 angstroms and 3.0 angstroms resolution. The carboxy-terminal globular domain has a beta-barrel fold with the same overall topology as the mammalian reovirus fibre (sigma1). However, the monomers of the sigmaC trimer show a more splayed-out arrangement than in the sigma1 structure. Also resolved are two triple beta-spiral repeats of the shaft or stalk domain. The presence in the sequence of heptad repeats amino-terminal to these triple beta-spiral repeats suggests that the unresolved portion of the shaft domain contains a triple alpha-helical coiled-coil structure. Implications for the function and stability of the sigmaC protein are discussed.

PubMed: 16236316
DOI: 10.1016/J.JMB.2005.09.034

Experimental method

X-RAY DIFFRACTION (3 Å)