2ntf

Crystal Structure of a Quorum-Quenching Antibody in Complex with an N-Acyl-L-Homoserine Lactone Analog

spinqualitylabelsall models 2ntf, resolution 3.18Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ntf is a 4 chain structure with sequence from Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.18Å Ligands: OHM Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q99LC4_MOUSE 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 PubMed A large number of Gram-negative bacteria employ N-acyl homoserine lactones (AHLs) as signaling molecules in quorum sensing, which is a population density-dependent mechanism to coordinate gene expression. Antibody RS2-1G9 was elicited against a lactam mimetic of the N-acyl homoserine lactone and represents the only reported monoclonal antibody that recognizes the naturally-occuring N-acyl homoserine lactone with high affinity. Due to its high cross-reactivity, RS2-1G9 showed remarkable inhibition of quorum sensing signaling in Pseudomonas aeruginosa, a common opportunistic pathogen in humans. The crystal structure of Fab RS2-1G9 in complex with a lactam analog revealed complete encapsulation of the polar lactam moiety in the antibody-combining site. This mode of recognition provides an elegant immunological solution for tight binding to an aliphatic, lipid-like ligand with a small head group lacking typical haptenic features, such as aromaticity or charge, which are often incorporated into hapten design to generate high-affinity antibodies. The ability of RS2-1G9 to discriminate between closely related AHLs is conferred by six hydrogen bonds to the ligand. Conversely, cross-reactivity of RS2-1G9 towards the lactone is likely to originate from conservation of these hydrogen bonds as well as an additional hydrogen bond to the oxygen of the lactone ring. A short, narrow tunnel exiting at the protein surface harbors a portion of the acyl chain and would not allow entry of the head group. The crystal structure of the antibody without its cognate lactam or lactone ligands revealed a considerably altered antibody-combining site with a closed binding pocket. Curiously, a completely buried ethylene glycol molecule mimics the lactam ring and, thus, serves as a surrogate ligand. The detailed structural delineation of this quorum-quenching antibody will aid further development of an antibody-based therapy against bacterial pathogens by interference with quorum sensing. Crystal structures of a quorum-quenching antibody.,Debler EW, Kaufmann GF, Kirchdoerfer RN, Mee JM, Janda KD, Wilson IA J Mol Biol. 2007 May 18;368(5):1392-402. Epub 2007 Mar 6. PMID:17400249 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Antibody 3D structures 3D structures of non-human antibody

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