1l7i

<table><tr><td colspan='2'>[[1l7i]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1L7I OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1L7I FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

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== Publication Abstract from PubMed ==

Shotgun scanning combinatorial mutagenesis was used to study the antigen-binding site of Fab2C4, a humanized monoclonal antibody fragment that binds to the extracellular domain of the human oncogene product ErbB2. Essentially all the residues in the Fab2C4 complementarity determining regions (CDRs) were alanine-scanned using phage-displayed libraries that preferentially allowed side-chains to vary as the wild-type or alanine. A separate homolog-scan was performed using libraries that allowed side-chains to vary only as the wild-type or a similar amino acid residue. Following binding selections to isolate functional clones, DNA sequencing was used to determine the wild-type/mutant ratios at each varied position, and these ratios were used to assess the contributions of each side-chain to antigen binding. The alanine-scan revealed that most of the side-chains that contribute to antigen binding are located in the heavy chain, and the Fab2C4 three-dimensional structure revealed that these residues fall into two groups. The first group consists of solvent-exposed residues which likely make energetically favorable contacts with the antigen and thus comprise the functional-binding epitope. The second group consists of buried residues with side-chains that pack against other CDR residues and apparently act as scaffolding to maintain the functional epitope in a binding-competent conformation. The homolog-scan involved subtle mutations, and as a result, only a subset of the side-chains that were intolerant to alanine substitutions were also intolerant to homologous substitutions. In particular, the 610 A2 functional epitope surface revealed by alanine-scanning shrunk to only 369 A2 when mapped with homologous substitutions, suggesting that this smaller subset of side-chains may be involved in more precise contacts with the antigen. The results validate shotgun scanning as a rapid and accurate method for determining the functional contributions of individual side-chains involved in protein-protein interactions.

Comprehensive functional maps of the antigen-binding site of an anti-ErbB2 antibody obtained with shotgun scanning mutagenesis.,Vajdos FF, Adams CW, Breece TN, Presta LG, de Vos AM, Sidhu SS J Mol Biol. 2002 Jul 5;320(2):415-28. PMID:12079396<ref>PMID:12079396</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Human]]

[[Category: Adams, C W]]

[[Category: Breece, T N]]

[[Category: Presta, L G]]

[[Category: Sidhu, S S]]

[[Category: Vajdos, F F]]

[[Category: Vos, A M.de]]

[[Category: Immune system]]