3mu3
Crystal structure of chicken MD-1 complexed with lipid IVaCrystal structure of chicken MD-1 complexed with lipid IVa
Structural highlights
FunctionLY86_CHICK May cooperate with CD180 and TLR4 to mediate the innate immune response to bacterial lipopolysaccharide (LPS) and cytokine production. Important for efficient CD180 cell surface expression (By similarity). Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedLipopolysaccharide (LPS) of Gram-negative bacteria is a common pathogen-associated molecular pattern (PAMP) that induces potent innate immune responses. The host immune response against LPS is triggered by myeloid differentiation factor 2 (MD-2) in association with Toll-like receptor 4 (TLR4) on the cell surface. The MD-2/TLR4-mediated LPS response is regulated by the evolutionarily related complex of MD-1 and Toll-like receptor homolog RP105. Here, we report crystallographic and biophysical data that demonstrate a previously unidentified direct interaction of MD-1 with LPS. The crystal structure of chicken MD-1 (cMD-1) at 2.0 A resolution exhibits a beta-cup-like fold, similar to MD-2, that encloses a hydrophobic cavity between the two beta-sheets. A lipid-like moiety was observed inside the cavity, suggesting the possibility of a direct MD-1/LPS interaction. LPS was subsequently identified as an MD-1 ligand by native gel electrophoresis and gel filtration analyses. The crystal structure of cMD-1 with lipid IVa, an LPS precursor, at 2.4 A resolution revealed that the lipid inserts into the deep hydrophobic cavity of the beta-cup-like structure, but with some important differences compared with MD-2. These findings suggest that soluble MD-1 alone, in addition to its complex with RP105, can regulate host LPS sensitivity. Crystal structure of soluble MD-1 and its interaction with lipid IVa.,Yoon SI, Hong M, Han GW, Wilson IA Proc Natl Acad Sci U S A. 2010 Jun 15;107(24):10990-5. Epub 2010 Jun 1. PMID:20534476[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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