Riepl, Hubert and Scharf, Birgit and Schmitt, Ruediger and Kalbitzer, Hans Robert and Maurer, Till (2004) Solution structures of the inactive and BeF3-activated response regulator CheY2. JOURNAL OF MOLECULAR BIOLOGY, 338 (2). pp. 287-297. ISSN 0022-2836, 1089-8638
Full text not available from this repository. (Request a copy)Abstract
The chemotactic signalling chain to the flagellar motor of Sinorhizobium meliloti features a new type of response regulator, CheY2. CheY2 activated by phosphorylation (CheY2-P) controls the rotary speed of the flagellar motor (instead of reversing the sense of rotation), and it is efficiently dephosphorylated by phospho-retrotransfer to the cognate kinase, CheA. Here, we report the NMR solution structures of the Mg2+-complex of inactive CheY2, and of activated CheY2-BeF3, a stable analogue of CheY2-P, to an overall root mean square deviation of 0.042 nm and 0.027 nm, respectively. The 14 kDa. CheY2 protein exhibits a characteristic open (alpha/beta)(5) conformation. Modification of CheY2 by BeF3- leads to large conformational changes of the protein, which are in the limits of error identical with those observed by phosphorylation of the active-centre residue Asp58. In BeF3-activated CheY2, the position of Thr88-OH favours the formation of a hydrogen bond with the active site, Asp58-BeF3, similar to BeF3-activated CheY from Escherichia coli. In contrast to E. coli, this reorientation is not involved in a Tyr-Thr-coupling mechanism, that propagates the signal from the incoming phosphoryl group to the C-terminally located FliM-binding surface. Rather, a rearrangement of the Phe59 side-chain to interact with Ile86-Leu95-Val96 along with a displacement of alpha4 towards beta5 is stabilised in S. meliloti. The resulting, activation-induced, compact alpha4-beta5-alpha5 surface forms a unique binding domain suited for specific interaction with and signalling to a rotary motor that requires a gradual speed control. We propose that these new features of response regulator activation, compared to other two-component systems, are the key for the observed unique phosphorylation, dephosphorylation and motor control mechanisms in S. meliloti. (C) 2004 Elsevier Ltd. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CHEMOTAXIS SIGNAL-TRANSDUCTION; PROTEIN SECONDARY STRUCTURE; CHEMICAL-SHIFT INDEX; FIXJ RECEIVER DOMAIN; BACTERIAL CHEMOTAXIS; RHIZOBIUM-MELILOTI; SINORHIZOBIUM-MELILOTI; NMR-SPECTROSCOPY; ESCHERICHIA-COLI; ACTIVATED CHEY; chemotaxis; domain interaction; NMR structure; response regulator; retro-phosphorylation |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Dr. Hans Robert Kalbitzer Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 21 Jul 2021 08:14 |
| Last Modified: | 21 Jul 2021 08:14 |
| URI: | https://pred.uni-regensburg.de/id/eprint/37737 |
Actions (login required)
 |
View Item |
