1tjl
From Proteopedia
(New page: 200px<br /><applet load="1tjl" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tjl, resolution 2.00Å" /> '''Crystal structure of...) |
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| - | [[Image:1tjl.gif|left|200px]]<br /><applet load="1tjl" size=" | + | [[Image:1tjl.gif|left|200px]]<br /><applet load="1tjl" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1tjl, resolution 2.00Å" /> | caption="1tjl, resolution 2.00Å" /> | ||
'''Crystal structure of transcription factor DksA from E. coli'''<br /> | '''Crystal structure of transcription factor DksA from E. coli'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Bacterial transcription is regulated by the alarmone ppGpp, which binds | + | Bacterial transcription is regulated by the alarmone ppGpp, which binds near the catalytic site of RNA polymerase (RNAP) and modulates its activity. We show that the DksA protein is a crucial component of ppGpp-dependent regulation. The 2.0 A resolution structure of Escherichia coli DksA reveals a globular domain and a coiled coil with two highly conserved Asp residues at its tip that is reminiscent of the transcript cleavage factor GreA. This structural similarity suggests that DksA coiled coil protrudes into the RNAP secondary channel to coordinate a ppGpp bound Mg2+ ion with the Asp residues, thereby stabilizing the ppGpp-RNAP complex. Biochemical analysis demonstrates that DksA affects transcript elongation, albeit differently from GreA; augments ppGpp effects on initiation; and binds directly to RNAP, positioning the Asp residues near the active site. Substitution of these residues eliminates the synergy between DksA and ppGpp. Thus, the secondary channel emerges as a common regulatory entrance for transcription factors. |
==About this Structure== | ==About this Structure== | ||
| - | 1TJL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1TJL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TJL OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Artsimovitch, I.]] | [[Category: Artsimovitch, I.]] | ||
[[Category: Perederina, A.]] | [[Category: Perederina, A.]] | ||
| - | [[Category: RSGI, RIKEN | + | [[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]] |
[[Category: Svetlov, V.]] | [[Category: Svetlov, V.]] | ||
| - | [[Category: Vassylyev, D | + | [[Category: Vassylyev, D G.]] |
| - | [[Category: Vassylyeva, M | + | [[Category: Vassylyeva, M N.]] |
[[Category: Yokoyama, S.]] | [[Category: Yokoyama, S.]] | ||
[[Category: ZN]] | [[Category: ZN]] | ||
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[[Category: transcription factor]] | [[Category: transcription factor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:14:11 2008'' |
Revision as of 13:14, 21 February 2008
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Crystal structure of transcription factor DksA from E. coli
Overview
Bacterial transcription is regulated by the alarmone ppGpp, which binds near the catalytic site of RNA polymerase (RNAP) and modulates its activity. We show that the DksA protein is a crucial component of ppGpp-dependent regulation. The 2.0 A resolution structure of Escherichia coli DksA reveals a globular domain and a coiled coil with two highly conserved Asp residues at its tip that is reminiscent of the transcript cleavage factor GreA. This structural similarity suggests that DksA coiled coil protrudes into the RNAP secondary channel to coordinate a ppGpp bound Mg2+ ion with the Asp residues, thereby stabilizing the ppGpp-RNAP complex. Biochemical analysis demonstrates that DksA affects transcript elongation, albeit differently from GreA; augments ppGpp effects on initiation; and binds directly to RNAP, positioning the Asp residues near the active site. Substitution of these residues eliminates the synergy between DksA and ppGpp. Thus, the secondary channel emerges as a common regulatory entrance for transcription factors.
About this Structure
1TJL is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Regulation through the secondary channel--structural framework for ppGpp-DksA synergism during transcription., Perederina A, Svetlov V, Vassylyeva MN, Tahirov TH, Yokoyama S, Artsimovitch I, Vassylyev DG, Cell. 2004 Aug 6;118(3):297-309. PMID:15294156
Page seeded by OCA on Thu Feb 21 15:14:11 2008
Categories: Escherichia coli | Single protein | Artsimovitch, I. | Perederina, A. | RSGI, RIKEN Structural Genomics/Proteomics Initiative. | Svetlov, V. | Vassylyev, D G. | Vassylyeva, M N. | Yokoyama, S. | ZN | Dksa | Ppgpp | Riken structural genomics/proteomics initiative | Rna polymerase | Rsgi | Stringent response | Structural genomics | Transcription factor
