1p6q
From Proteopedia
(New page: 200px<br /><applet load="1p6q" size="450" color="white" frame="true" align="right" spinBox="true" caption="1p6q" /> '''NMR Structure of the Response regulator CheY...) |
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'''NMR Structure of the Response regulator CheY2 from Sinorhizobium meliloti, complexed with Mg++'''<br /> | '''NMR Structure of the Response regulator CheY2 from Sinorhizobium meliloti, complexed with Mg++'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The chemotactic signalling chain to the flagellar motor of Sinorhizobium | + | 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. |
==About this Structure== | ==About this Structure== | ||
| - | 1P6Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti]. Full crystallographic information is available from [http:// | + | 1P6Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P6Q OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Sinorhizobium meliloti]] | [[Category: Sinorhizobium meliloti]] | ||
| - | [[Category: Kalbitzer, H | + | [[Category: Kalbitzer, H R.]] |
[[Category: Maurer, T.]] | [[Category: Maurer, T.]] | ||
[[Category: Riepl, H.]] | [[Category: Riepl, H.]] | ||
| - | [[Category: SPINE, Structural | + | [[Category: SPINE, Structural Proteomics in Europe.]] |
[[Category: Scharf, B.]] | [[Category: Scharf, B.]] | ||
[[Category: Schmitt, R.]] | [[Category: Schmitt, R.]] | ||
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[[Category: structural proteomics in europe]] | [[Category: structural proteomics in europe]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:25:42 2008'' |
Revision as of 12:25, 21 February 2008
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NMR Structure of the Response regulator CheY2 from Sinorhizobium meliloti, complexed with Mg++
Overview
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.
About this Structure
1P6Q is a Single protein structure of sequence from Sinorhizobium meliloti. Full crystallographic information is available from OCA.
Reference
Solution structures of the inactive and BeF3-activated response regulator CheY2., Riepl H, Scharf B, Schmitt R, Kalbitzer HR, Maurer T, J Mol Biol. 2004 Apr 23;338(2):287-97. PMID:15066432
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