1ql2

INOVIRUS (FILAMENTOUS BACTERIOPHAGE) STRAIN PF1 MAJOR COAT PROTEIN ASSEMBLYINOVIRUS (FILAMENTOUS BACTERIOPHAGE) STRAIN PF1 MAJOR COAT PROTEIN ASSEMBLY

Structural highlights 1ql2 is a 3 chain structure with sequence from Pseudomonas phage pf1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1ql1, 2ifm, 2ifn, 3ifm, 4ifm, 1pfi Resources: FirstGlance, OCA, RCSB, PDBsum Publication Abstract from PubMed The major coat protein in the capsid of Pf1 filamentous bacteriophage (Inovirus) forms a helical assembly of about 7000 identical protein subunits, each of which contains 46 amino-acid residues and can be closely approximated by a single gently curved alpha-helix. Since the viral DNA occupies the core of the tubular capsid and appears to make no significant specific interactions with the capsid proteins, the capsid is a simple model system for the study of the static and dynamic properties of alpha-helix assembly. The capsid undergoes a reversible temperature-induced structural transition at about 283 K between two slightly different helix forms. The two forms can coexist without an intermediate state, consistent with a first-order structural phase transition. The molecular model of the higher temperature form was refined using improved X-ray fibre diffraction data and new refinement and validation methods. The refinement indicates that the two forms are related by a change in the orientation of the capsid subunits within the virion, without a significant change in local conformation of the subunits. On the higher temperature diffraction pattern there is a region of observed intensity that is not consistent with a simple helix of identical subunits; it is proposed that the structure involves groups of three subunits which each have a slightly different orientation within the group. The grouping of subunits suggests that a change in subunit libration frequency could be the basis of the Pf1 structural transition; calculations from the model are used to explore this idea. The molecular structure and structural transition of the alpha-helical capsid in filamentous bacteriophage Pf1.,Welsh LC, Symmons MF, Marvin DA Acta Crystallogr D Biol Crystallogr. 2000 Feb;56(Pt 2):137-50. PMID:10666593 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 1ql2, resolution 3.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image