2hi5

Model for bacteriophage fd from cryo-EMModel for bacteriophage fd from cryo-EM

2hi5, resolution 8.00Å Show:Asymmetric Unit Biological Assembly Structural highlights 2hi5 is a 1 chain structure with sequence from Bpfd. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [CAPSD_BPFD] Self assembles to form a helical capsid wrapping up the viral genomic DNA. The capsid displays a filamentous structure with a length of 760-1950 nm and a width of 6-8 nm. The virion assembly and budding take place at the host inner membrane (By similarity). Publication Abstract from PubMed Many thin helical polymers, including bacterial pili and filamentous bacteriophage, have been seen as refractory to high-resolution studies by electron microscopy. Studies of the quaternary structure of such filaments have depended upon techniques such as modeling or X-ray fiber diffraction, given that direct visualization of the subunit organization has not been possible. We report the first image reconstruction of a filamentous virus, bacteriophage fd, by cryoelectron microscopy. Although these thin ( approximately 70 A in diameter) rather featureless filaments scatter weakly, we have been able to achieve a nominal resolution of approximately 8 A using an iterative helical reconstruction procedure. We show that two different conformations of the virus exist, and that in both states the subunits are packed differently than in conflicting models previously proposed on the basis of X-ray fiber diffraction or solid-state NMR studies. A significant fraction of the population of wild-type fd is either disordered or in multiple conformational states, while in the presence of the Y21M mutation, this heterogeneity is greatly reduced, consistent with previous observations. These results show that new computational approaches to helical reconstruction can greatly extend the ability to visualize heterogeneous protein polymers at a reasonably high resolution. The structure of a filamentous bacteriophage.,Wang YA, Yu X, Overman S, Tsuboi M, Thomas GJ Jr, Egelman EH J Mol Biol. 2006 Aug 11;361(2):209-15. Epub 2006 Jun 30. PMID:16843489 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.