| Dokumentenart: | Artikel | ||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Titel eines Journals oder einer Zeitschrift: | Journal of molecular biology | ||||||||||||||||||||||||||||||||||||
| Verlag: | Elsevier | ||||||||||||||||||||||||||||||||||||
| Band: | 338 | ||||||||||||||||||||||||||||||||||||
| Nummer des Zeitschriftenheftes oder des Kapitels: | 2 | ||||||||||||||||||||||||||||||||||||
| Seitenbereich: | S. 287-297 | ||||||||||||||||||||||||||||||||||||
| Datum: | 2004 | ||||||||||||||||||||||||||||||||||||
| Institutionen: | Biologie und Vorklinische Medizin > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Dr. Hans Robert Kalbitzer | ||||||||||||||||||||||||||||||||||||
| Identifikationsnummer: |
| ||||||||||||||||||||||||||||||||||||
| Klassifikation: |
| ||||||||||||||||||||||||||||||||||||
| Dewey-Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften, Biologie | ||||||||||||||||||||||||||||||||||||
| Status: | Veröffentlicht | ||||||||||||||||||||||||||||||||||||
| Begutachtet: | Unbekannt / Keine Angabe | ||||||||||||||||||||||||||||||||||||
| An der Universität Regensburg entstanden: | Unbekannt / Keine Angabe | ||||||||||||||||||||||||||||||||||||
| Dokumenten-ID: | 16606 |
Zusammenfassung
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 ...
Zusammenfassung
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 Mg(2+)-complex of inactive CheY2, and of activated CheY2-BeF(3), 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 BeF(3)(-) 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 BeF(3)-activated CheY2, the position of Thr88-OH favours the formation of a hydrogen bond with the active site, Asp58-BeF(3), similar to BeF(3)-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.
Metadaten zuletzt geändert: 29 Sep 2021 07:38
Altmetric