1zda

PHAGE-SELECTED MINI PROTEIN A DOMAIN, Z38, NMR, 24 STRUCTURES

spinqualitylabelsall models 1zda, 24 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1zda is a 1 chain structure with sequence from Synthetic construct. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1zdb Resources: FirstGlance, OCA, RCSB, PDBsum Publication Abstract from PubMed The affinity between molecules depends both on the nature and presentation of the contacts. Here, we observe coupling of functional and structural elements when a protein binding domain is evolved to a smaller functional mimic. Previously, a 38-residue form of the 59-residue B-domain of protein A, termed Z38, was selected by phage display. Z38 contains 13 mutations and binds IgG only 10-fold weaker than the native B-domain. We present the solution structure of Z38 and show that it adopts a tertiary structure remarkably similar to that observed for the first two helices of B-domain in the B-domain/Fc complex [Deisenhofer, J. (1981) Biochemistry 20, 2361-2370], although it is significantly less stable. Based on this structure, we have improved on Z38 by designing a 34-residue disulfide-bonded variant (Z34C) that has dramatically enhanced stability and binds IgG with 9-fold higher affinity. The improved stability of Z34C led to NMR spectra with much greater chemical shift dispersion, resulting in a more precisely determined structure. Z34C, like Z38, has a structure virtually identical to the equivalent region from native protein A domains. The well-defined hydrophobic core of Z34C reveals key structural features that have evolved in this small, functional domain. Thus, the stabilized two-helix peptide, about half the size and having one-third of the remaining residues altered, accurately mimics both the structure and function of the native domain. Structural mimicry of a native protein by a minimized binding domain.,Starovasnik MA, Braisted AC, Wells JA Proc Natl Acad Sci U S A. 1997 Sep 16;94(19):10080-5. PMID:9294166 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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