2AF5

2.5A X-ray Structure of Engineered OspA protein

Summary for 2AF5

• Entry DOI: 10.2210/pdb2af5/pdb
• Descriptor: Engineered Outer Surface Protein A (OspA) with the inserted two beta-hairpins (2 entities in total)
• Functional Keywords: single-layer beta-sheet, beta-hairpin, repeat protein, de novo protein, immune system
• Biological source: Borrelia burgdorferi (Lyme disease spirochete); More
• Total number of polymer chains: 1
• Total formula weight: 32292.27

Authors

Makabe, K.,Mcelheny, D.,Tereshko, V.,Hilyard, A.,Koide, A.,Koide, S. (deposition date: 2005-07-25, release date: 2006-08-01, Last modification date: 2023-08-23)

Primary citation

Makabe, K.,McElheny, D.,Tereshko, V.,Hilyard, A.,Gawlak, G.,Yan, S.,Koide, A.,Koide, S.
Atomic structures of peptide self-assembly mimics.
Proc.Natl.Acad.Sci.Usa, 103:17753-17758, 2006

PubMed Abstract: Although the beta-rich self-assemblies are a major structural class for polypeptides and the focus of intense research, little is known about their atomic structures and dynamics due to their insoluble and noncrystalline nature. We developed a protein engineering strategy that captures a self-assembly segment in a water-soluble molecule. A predefined number of self-assembling peptide units are linked, and the beta-sheet ends are capped to prevent aggregation, which yields a mono-dispersed soluble protein. We tested this strategy by using Borrelia outer surface protein (OspA) whose single-layer beta-sheet located between two globular domains consists of two beta-hairpin units and thus can be considered as a prototype of self-assembly. We constructed self-assembly mimics of different sizes and determined their atomic structures using x-ray crystallography and NMR spectroscopy. Highly regular beta-sheet geometries were maintained in these structures, and peptide units had a nearly identical conformation, supporting the concept that a peptide in the regular beta-geometry is primed for self-assembly. However, we found small but significant differences in the relative orientation between adjacent peptide units in terms of beta-sheet twist and bend, suggesting their inherent flexibility. Modeling shows how this conformational diversity, when propagated over a large number of peptide units, can lead to a substantial degree of nanoscale polymorphism of self-assemblies.

PubMed: 17093048
DOI: 10.1073/pnas.0606690103

Experimental method

X-RAY DIFFRACTION (2.5 Å)