Structural organization and assembly of flagellar hook protein from Salmonella typhimurium.
Abstract
The terminal regions of monomeric hook protein from Salmonella typhimurium are known to be highly mobile and exposed to the solvent. Although hook protein exhibits an unusual far-UV circular dichroism spectrum, resembling that of random coil structures, our calorimetric experiments clearly demonstrate that the molecule has a compact ordered core. The compact part probably consists of three domains as suggested by deconvolution analysis of the calorimetric melting profiles. Secondary structure prediction, together with the analysis of far-UV circular dichroism spectra, has shown that the domains of monomeric hook protein contain beta-sheeted structures without significant alpha-helical content. The polymerization of hook protein is accompanied by the stabilization of its disordered terminal regions into a predominantly alpha-helical domain. Evaluation of circular dichroism data suggests that about 45 terminal residues are involved in helical segments. Coiled-coil prediction indicates that whereas the whole carboxy-terminal helical region of hook protein has a strong bundle-forming potential, there is only a single short amino-terminal segment exhibiting weak coiled-coil forming tendencies. The formation of alpha-helical bundles is commonly believed to be a key event during the polymerization of the axial structure of bacterial flagella. To clarify the role of helical bundle formation in hook assembly, proteolytic fragments of hook protein with truncations of various lengths in their carboxy-terminal disordered regions were generated, and their polymerization behavior was investigated. We found that even fragments completely lacking the main helix-forming carboxy-terminal regions can polymerize into filaments in vitro under appropriately high salt concentrations. Our results suggest that, although helical bundle formation may occur during self-assembly, governing precise subunit packing and playing an important role in the stabilization of hook filaments, it is not the principal interaction mainly responsible for the development of their filamentous structure. Study holds ProTherm entries: 2959 Extra Details: bacterial flagellum; hook protein; domain structure;,secondary structure; coiled-coil formation
Submission Details
ID: rBEbhuwy3
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:20 p.m.
Version: 1
Publication Details
Vonderviszt F;Závodszky P;Ishimura M;Uedaira H;Namba K,J. Mol. Biol. (1995) Structural organization and assembly of flagellar hook protein from Salmonella typhimurium. PMID:7658470Additional Information
Study Summary
Structure view and single mutant data analysis
Study data
| Colors: | D | E | R | H | K | S | T | N | Q | A | V | I | L | M | F | Y | W | C | G | P |
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Data Distribution
Studies with similar sequences (approximate matches)
Correlation with other assays (exact sequence matches)
Relevant PDB Entries
| Structure ID | Release Date | Resolution | Structure Title |
|---|---|---|---|
| 1WLG | 2004-11-02 | 1.8 | Crystal structure of FlgE31, a major fragment of the hook protein |
| 3A69 | 2009-12-15 | 7.1 | Atomic model of the bacterial flagellar hook based on docking an X-ray derived structure and terminal two alpha-helices into an 7.1 angstrom resolution cryoEM map |
| 2BGY | 2005-01-27 | 9.0 | Fit of the x-ray strucutre of the baterial flagellar hook fragment flge31 into an EM map from the hook of Caulobacter crescentus. |
| 2BGZ | 2005-01-27 | 9.0 | ATOMIC MODEL OF THE BACTERIAL FLAGELLAR BASED ON DOCKING AN X-RAY DERIVED HOOK STRUCTURE INTO AN EM MAP. |