4s1x

Crystal structure of HA2-Del-L2seM, Central Coiled-Coil from Influenza Hemagglutinin HA2 without Heptad Repeat Stutter

spinqualitylabelsall models 4s1x, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4s1x is a 6 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GOL NonStd Res: MSE Related: 4oxm, 4p67 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed The coiled-coil is one of the most ubiquitous and well studied protein structural motifs. Significant effort has been devoted to dissecting subtle variations of the typical heptad repeat sequence pattern that can designate larger topological features such as relative alpha-helical orientation and oligomer size. Here we report the X-ray structure of a model coiled-coil peptide, HA2-Del-L2seM, which forms an unanticipated core antiparallel dimer with potential sites for discrete higher-order multimerization (trimer or tetramer). In the X-ray structure, a third, partially-ordered alpha-helix is weakly associated with the antiparallel dimer and analytical ultracentrifugation experiments indicate the peptide forms a well-defined tetramer in solution. The HA2-Del-L2seM sequence is closely related to a parent model peptide, HA2-Del, which we previously reported adopts a parallel trimer; HA2-Del-L2seM differs by only hydrophobic leucine to selenomethione mutations and thus this subtle difference is sufficient to switch both relative alpha-helical topology and number of alpha-helices participating in the coiled-coil. Comparison of the X-ray structures of HA2-Del-L2seM (reported here) with the HA2-Del parent (reported previously) reveals novel interactions involving the selenomethionine residues that promote antiparallel coiled-coil configuration and preclude parallel trimer formation. These novel atomic insights are instructive for understanding subtle features that can affect coiled-coil topology and provide additional information for design of antiparallel coiled-coils. This article is protected by copyright. All rights reserved. A Switch from Parallel to Antiparallel Strand Orientation in a Coiled-Coil X-Ray Structure via Two Core Hydrophobic Mutations.,Malashkevich VN, Higgins CD, Almo SC, Lai JR Biopolymers. 2015 Mar 6. doi: 10.1002/bip.22631. PMID:25753192 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Hemagglutinin

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