1g6v

Complex of the camelid heavy-chain antibody fragment CAB-CA05 with bovine carbonic anhydraseComplex of the camelid heavy-chain antibody fragment CAB-CA05 with bovine carbonic anhydrase

Structural highlights 1g6v is a 2 chain structure with sequence from Bos taurus and Camelus dromedarius. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Related: 1f2x Activity: Carbonate dehydratase, with EC number 4.2.1.1 Resources: FirstGlance, OCA, RCSB, PDBsum Function [CAH2_BOVIN] Essential for bone resorption and osteoclast differentiation (By similarity). Reversible hydration of carbon dioxide. 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 Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A(2). For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 canonical structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular beta-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to 'humanize' a camel variable domain of heavy chain of heavy chain antibody (VHH) or to 'camelize' a human or a mouse variable domain of heavy chain of conventional antibody (VH). Antigen specificity and high affinity binding provided by one single loop of a camel single-domain antibody.,Desmyter A, Decanniere K, Muyldermans S, Wyns L J Biol Chem. 2001 Jul 13;276(28):26285-90. Epub 2001 May 7. PMID:11342547 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Antibody Carbonic anhydrase

spinqualitylabelsall models 1g6v, resolution 3.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image