4dzp

Crystal structure of the terminase small subunit gp1 with R48A mutation of the bacterial virus sf6

spinqualitylabelsall models 4dzp, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4dzp is a 2 chain structure with sequence from Shigella virus Sf6. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [Q716H4_BPSFV] Publication Abstract from PubMed In many DNA viruses, genome packaging is initiated by the small subunit of the packaging terminase, which specifically binds to the packaging signal on viral DNA and directs assembly of the terminase holoenzyme. We have experimentally mapped the DNA-interacting region on Shigella virus Sf6 terminase small subunit gp1, which occupies extended surface areas encircling the gp1 octamer, indicating that DNA wraps around gp1 through extensive contacts. High-resolution structures reveal large-scale motions of the gp1 DNA-binding domain mediated by the curved helix formed by residues 54-81 and an intermolecular salt bridge formed by residues Arg67 and Glu73, indicating remarkable structural plasticity underlying multivalent, pleomorphic gp1:DNA interactions. These results provide spatial restraints for protein:DNA interactions, which enable construction of a three-dimensional pseudo-atomic model for a DNA-packaging initiation complex assembled from the terminase small subunit and the packaging region on viral DNA. Our results suggest that gp1 functions as a DNA-spooling device, which may transform DNA into a specific architecture appropriate for interaction with and cleavage by the terminase large subunit prior to DNA translocation into viral procapsid. This may represent a common mechanism for the initiation step of DNA packaging in tailed double-stranded DNA bacterial viruses. Structural and Functional Studies of the Phage Sf6 Terminase Small Subunit Reveal a DNA-Spooling Device Facilitated by Structural Plasticity.,Zhao H, Kamau YN, Christensen TE, Tang L J Mol Biol. 2012 Oct 26;423(3):413-26. doi: 10.1016/j.jmb.2012.07.016. Epub 2012 , Jul 31. PMID:22858866 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Terminase 3D Structures

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