Abstract
The crystal structure of a soluble form of Borrelia burgdorferi outer surface protein A (OspA) complexed with the Fab fragment of a monoclonal antibody has revealed an unusual structure that has a repetitive antiparallel beta topology with a nonglobular, single layer beta-sheet connecting the globular N- and C-terminal domains. Earlier NMR studies have shown that the local structure of OspA including the single layer beta-sheet is similar to the crystal structure. Here we report a small angle X-ray scattering (SAXS) study of the global conformation of OspA in solution. The radius of gyration (Rg) and the length distribution function (P(r)) of OspA measured by SAXS in solution are nearly identical to the calculated ones from the crystal structure, respectively. The NMR and SAXS experiments complement each other to show that OspA including the central single-layer beta-sheet is a stable structure in solution, and that the OspA crystal structure represents the predominant solution conformation of the protein.
Full Text
The Full Text of this article is available as a PDF (1.0 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Dill K. A. Dominant forces in protein folding. Biochemistry. 1990 Aug 7;29(31):7133–7155. doi: 10.1021/bi00483a001. [DOI] [PubMed] [Google Scholar]
- Dunn J. J., Lade B. N., Barbour A. G. Outer surface protein A (OspA) from the Lyme disease spirochete, Borrelia burgdorferi: high level expression and purification of a soluble recombinant form of OspA. Protein Expr Purif. 1990 Nov;1(2):159–168. doi: 10.1016/1046-5928(90)90011-m. [DOI] [PubMed] [Google Scholar]
- KAUZMANN W. Some factors in the interpretation of protein denaturation. Adv Protein Chem. 1959;14:1–63. doi: 10.1016/s0065-3233(08)60608-7. [DOI] [PubMed] [Google Scholar]
- Li H., Dunn J. J., Luft B. J., Lawson C. L. Crystal structure of Lyme disease antigen outer surface protein A complexed with an Fab. Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):3584–3589. doi: 10.1073/pnas.94.8.3584. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pham T. N., Koide A., Koide S. A stable single-layer beta-sheet without a hydrophobic core. Nat Struct Biol. 1998 Feb;5(2):115–119. doi: 10.1038/nsb0298-115. [DOI] [PubMed] [Google Scholar]
- Pham T. N., Koide S. NMR studies of Borrelia burgdorferi OspA, a 28 kDa protein containing a single-layer beta-sheet. J Biomol NMR. 1998 May;11(4):407–414. doi: 10.1023/a:1008246908142. [DOI] [PubMed] [Google Scholar]
- Tjandra N., Garrett D. S., Gronenborn A. M., Bax A., Clore G. M. Defining long range order in NMR structure determination from the dependence of heteronuclear relaxation times on rotational diffusion anisotropy. Nat Struct Biol. 1997 Jun;4(6):443–449. doi: 10.1038/nsb0697-443. [DOI] [PubMed] [Google Scholar]