1.2 °A resolution crystal structure of Escherichia coli WrbA holoprotein

0399208 - ÚVGZ 2014 RIV US eng J - Journal Article
Kishko, Iryna - Carey, J. - Řeha, David - Brynda, Jiří - Winkler, R. - Harish, B. - Guerra, R. - Ettrichová, Olga - Kukačka, Zdeněk - Sheryemyetyeva, O. - Novák, Petr - Kutý, Michal - Kutá-Smatanová, Ivana - Ettrich, Rüdiger - Lapkouski, Mikalai
1.2 °A resolution crystal structure of Escherichia coli WrbA holoprotein.
Acta Crystallographica Section D-Biological Crystallography. Roč. 69, č. 9 (2013), s. 1748-1757. ISSN 0907-4449
R&D Projects: GA ČR GAP207/10/1934
Institutional support: RVO:67179843 ; RVO:68378050 ; RVO:61388971
Keywords : HPLC * Nqo1 * diaphorase * flavodoxin * methionine sulfoxide * thin-layer chromatography
Subject RIV: CE - Biochemistry; CE - Biochemistry (MBU-M); EB - Genetics ; Molecular Biology (UMG-J)
Impact factor: 7.232, year: 2013

The Escherichia coli protein WrbA, an FMN-dependent NAD(P)H:quinone oxidoreductase, was crystallized under new conditions in the presence of FAD or the native cofactor FMN. Slow-growing deep yellow crystals formed with FAD display the tetragonal bipyramidal shape typical for WrbA and diffract to 1.2 Å resolution, the highest yet reported. Faster-growing deep yellow crystals formed with FMN display an atypical shape, but diffract to only 1.6 Å resolution and are not analysed further here. The 1.2 Å resolution structure detailed here revealed only FMN in the active site and no electron density that can accommodate the missing parts of FAD. The very high resolution supports the modelling of the FMN isoalloxazine with a small but distinct propeller twist, apparently the first experimental observation of this predicted conformation, which appears to be enforced by the protein through a network of hydrogen bonds. Comparison of the electron density of the twisted isoalloxazine ring with the results of QM/MM simulations is compatible with the oxidized redox state. The very high resolution also supports the unique refinement of Met10 as the sulfoxide, confirmed by mass spectrometry. Bond lengths, intramolecular distances, and the pattern of hydrogen-bond donors and acceptors suggest the cofactor may interact with Met10. Slow incorporation of FMN, which is present as a trace contaminant in stocks of FAD, into growing crystals may be responsible for the near-atomic resolution, but a direct effect of the conformation of FMN and/or Met10 sulfoxide cannot be ruled out.
Permanent Link: http://hdl.handle.net/11104/0226529