2PI3

The crystal structure of OspA mutant

Summary for 2PI3

• Entry DOI: 10.2210/pdb2pi3/pdb
• Related: 2OL6 2OL7 2OL8 2OY1 2OY5 2OY7 2OY8 2OYB
• Descriptor: Outer surface protein A (2 entities in total)
• Functional Keywords: beta sheet, membrane protein
• Biological source: Borrelia burgdorferi (Lyme disease spirochete)
• Total number of polymer chains: 1
• Total formula weight: 26523.58

Authors

Biancalana, M.,Makabe, K.,Terechko, V.,Koide, S. (deposition date: 2007-04-12, release date: 2008-05-27, Last modification date: 2023-08-30)

Primary citation

Biancalana, M.,Makabe, K.,Yan, S.,Koide, S.
Aromatic cluster mutations produce focal modulations of beta-sheet structure.
Protein Sci., 24:841-849, 2015

PubMed Abstract: Site-directed mutagenesis is a powerful tool for altering the structure and function of proteins in a focused manner. Here, we examined how a model β-sheet protein could be tuned by mutation of numerous surface-exposed residues to aromatic amino acids. We designed these aromatic side chain "clusters" at highly solvent-exposed positions in the flat, single-layer β-sheet of Borrelia outer surface protein A (OspA). This unusual β-sheet scaffold allows us to interrogate the effects of these mutations in the context of well-defined structure but in the absence of the strong scaffolding effects of globular protein architecture. We anticipated that the introduction of a cluster of aromatic amino acid residues on the β-sheet surface would result in large conformational changes and/or stabilization and thereby provide new means of controlling the properties of β-sheets. Surprisingly, X-ray crystal structures revealed that the introduction of aromatic clusters produced only subtle conformational changes in the OspA β-sheet. Additionally, despite burying a large degree of hydrophobic surface area, the aromatic cluster mutants were slightly less stable than the wild-type scaffold. These results thereby demonstrate that the introduction of aromatic cluster mutations can serve as a means for subtly modulating β-sheet conformation in protein design.

PubMed: 25645104
DOI: 10.1002/pro.2657

Experimental method

X-RAY DIFFRACTION (1.4 Å)