2OY1

The crystal structure of OspA mutant

Summary for 2OY1

• Entry DOI: 10.2210/pdb2oy1/pdb
• Related: 2OL6 2OL7 2OL8 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: 26210.35

Authors

Makabe, K.,Terechko, V.,Koide, S. (deposition date: 2007-02-21, release date: 2007-12-11, Last modification date: 2023-08-30)

Primary citation

Makabe, K.,Yan, S.,Tereshko, V.,Gawlak, G.,Koide, S.
beta-Strand Flipping and Slipping Triggered by Turn Replacement Reveal the Opportunistic Nature of beta-Strand Pairing
J.Am.Chem.Soc., 129:14661-14669, 2007

PubMed Abstract: We investigated how the register between adjacent beta-strands is specified using a series of mutants of the single-layer beta-sheet (SLB) in Borrelia OspA. The single-layer architecture of this system eliminates structural restraints imposed by a hydrophobic core, enabling us to address this question. A critical turn (turn 9/10) in the SLB was replaced with a segment with an intentional structural mismatch. Its crystal structure revealed a one-residue insertion into the central beta-strand (strand 9) of the SLB. This insertion triggered a surprisingly large-scale structural rearrangement: (i) the central strand (strand 9) was shifted by one residue, causing the strand to flip with respect to the adjacent beta-strands and thus completely disrupting the native side-chain contacts; (ii) the three-residue turn located on the opposite end of the beta-strand (turn 8/9) was pushed into its preceding beta-strand (strand 8); (iii) the register between strands 8 and 9 was shifted by three residues. Replacing the original sequence for turn 8/9 with a stronger turn motif restored the original strand register but still with a flipped beta-strand 9. The stability differences of these distinct structures were surprisingly small, consistent with an energy landscape where multiple low-energy states with different beta-sheet configurations exist. The observed conformations can be rationalized in terms of maximizing the number of backbone H-bonds. These results suggest that adjacent beta-strands "stick" through the use of factors that are not highly sequence specific and that beta-strands could slide back and forth relatively easily in the absence of external elements such as turns and tertiary packing.

PubMed: 17985889
DOI: 10.1021/ja074252c

Experimental method

X-RAY DIFFRACTION (1.86 Å)