2I5V

Crystal structure of OspA mutant

Summary for 2I5V

• Entry DOI: 10.2210/pdb2i5v/pdb
• Descriptor: Outer surface protein A, TETRAETHYLENE GLYCOL (3 entities in total)
• Functional Keywords: beta-sheet, de novo protein
• Biological source: Borrelia burgdorferi (Lyme disease spirochete)
• Total number of polymer chains: 1
• Total formula weight: 26874.26

Authors

Makabe, K.,Terechko, V.,Koide, S. (deposition date: 2006-08-25, release date: 2007-12-25, Last modification date: 2023-08-30)

Primary citation

Makabe, K.,Biancalana, M.,Yan, S.,Tereshko, V.,Gawlak, G.,Miller-Auer, H.,Meredith, S.C.,Koide, S.
High-Resolution Structure of a Self-Assembly-Competent Form of a Hydrophobic Peptide Captured in a Soluble β-Sheet Scaffold.
J.Mol.Biol., 378:459-467, 2008

PubMed Abstract: beta-Rich self-assembly is a major structural class of polypeptides, but still little is known about its atomic structures and biophysical properties. Major impediments for structural and biophysical studies of peptide self-assemblies include their insolubility and heterogeneous composition. We have developed a model system, termed peptide self-assembly mimic (PSAM), based on the single-layer beta-sheet of Borrelia outer surface protein A. PSAM allows for the capture of a defined number of self-assembly-like peptide repeats within a water-soluble protein, making structural and energetic studies possible. In this work, we extend our PSAM approach to a highly hydrophobic peptide sequence. We show that a penta-Ile peptide (Ile(5)), which is insoluble and forms beta-rich self-assemblies in aqueous solution, can be captured within the PSAM scaffold in a form capable of self-assembly. The 1.1-A crystal structure revealed that the Ile(5) stretch forms a highly regular beta-strand within this flat beta-sheet. Self-assembly models built with multiple copies of the crystal structure of the Ile(5) peptide segment showed no steric conflict, indicating that this conformation represents an assembly-competent form. The PSAM retained high conformational stability, suggesting that the flat beta-strand of the Ile(5) stretch primed for self-assembly is a low-energy conformation of the Ile(5) stretch and rationalizing its high propensity for self-assembly. The ability of the PSAM to "solubilize" an otherwise insoluble peptide stretch suggests the potential of the PSAM approach to the characterization of self-assembling peptides.

PubMed: 18367205
DOI: 10.1016/j.jmb.2008.02.051

Experimental method

X-RAY DIFFRACTION (1.1 Å)