1a15
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| , resolution 2.2Å | |||||||
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| Ligands: | |||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
SDF-1ALPHA
OverviewOverview
Stromal cell-derived factor-1alpha (SDF-1alpha ) is a member of the chemokine superfamily and functions as a growth factor and chemoattractant through activation of CXCR4/LESTR/Fusin, a G protein-coupled receptor. This receptor also functions as a coreceptor for T-tropic syncytium-inducing strains of HIV-1. SDF-1alpha antagonizes infectivity of these strains by competing with gp120 for binding to the receptor. The crystal structure of a variant SDF-1alpha ([N33A]SDF-1alpha ) prepared by total chemical synthesis has been refined to 2.2-A resolution. Although SDF-1alpha adopts a typical chemokine beta-beta-beta-alpha topology, the packing of the alpha-helix against the beta-sheet is strikingly different. Comparison of SDF-1alpha with other chemokine structures confirms the hypothesis that SDF-1alpha may be either an ancestral protein from which all other chemokines evolved or the chemokine that is the least divergent from a primordial chemokine. The structure of SDF-1alpha reveals a positively charged surface ideal for binding to the negatively charged extracellular loops of the CXCR4 HIV-1 coreceptor. This ionic complementarity is likely to promote the interaction of the mobile N-terminal segment of SDF-1alpha with interhelical sites of the receptor, resulting in a biological response.
About this StructureAbout this Structure
1A15 is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of chemically synthesized [N33A] stromal cell-derived factor 1alpha, a potent ligand for the HIV-1 "fusin" coreceptor., Dealwis C, Fernandez EJ, Thompson DA, Simon RJ, Siani MA, Lolis E, Proc Natl Acad Sci U S A. 1998 Jun 9;95(12):6941-6. PMID:9618518
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