2eul
From Proteopedia
(New page: 200px<br /><applet load="2eul" size="350" color="white" frame="true" align="right" spinBox="true" caption="2eul, resolution 2.40Å" /> '''Structure of the tra...) |
|||
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
| - | Gre factors enhance the intrinsic endonucleolytic activity of RNA | + | Gre factors enhance the intrinsic endonucleolytic activity of RNA polymerase to rescue arrested transcription complexes and are thought to confer the high fidelity and processivity of RNA synthesis. The Gre factors insert the extended alpha-helical coiled-coil domains into the RNA polymerase secondary channel to position two invariant acidic residues at the coiled-coil tip near the active site to stabilize the catalytic metal ion. Gfh1, a GreA homolog from Thermus thermophilus, inhibits rather than activates RNA cleavage. Here we report the structure of the T. thermophilus Gfh1 at 2.4 A resolution revealing a two-domain architecture closely resembling that of GreA. However, the interdomain orientation is strikingly distinct (approximately 162 degrees rotation) between the two proteins. In contrast to GreA, which has two acidic residues on a well fixed self-stabilized alpha-turn, the tip of the Gfh1 coiled-coil is flexible and contains four acidic residues. This difference is likely the key to the Gre functional diversity, while Gfh1 inhibits exo- and endonucleolytic cleavage, RNA synthesis, and pyrophosphorolysis, GreA enhances only the endonucleolytic cleavage. We propose that Gfh1 acidic residues stabilize the RNA polymerase active center in a catalytically inactive configuration through Mg2+-mediated interactions. The excess of the acidic residues and inherent flexibility of the coiled-coil tip might allow Gfh1 to adjust its activity to structurally distinct substrates, thereby inhibiting diverse catalytic reactions of RNA polymerase. |
==About this Structure== | ==About this Structure== | ||
| Line 15: | Line 15: | ||
[[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: Symersky, J.]] | [[Category: Symersky, J.]] | ||
| - | [[Category: Vassylyev, D | + | [[Category: Vassylyev, D G.]] |
| - | [[Category: Vassylyeva, M | + | [[Category: Vassylyeva, M N.]] |
[[Category: ZN]] | [[Category: ZN]] | ||
[[Category: gfh1]] | [[Category: gfh1]] | ||
| Line 28: | Line 28: | ||
[[Category: transcription factor]] | [[Category: transcription factor]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:14:39 2008'' |
Revision as of 15:14, 21 February 2008
|
Structure of the transcription factor Gfh1.
Overview
Gre factors enhance the intrinsic endonucleolytic activity of RNA polymerase to rescue arrested transcription complexes and are thought to confer the high fidelity and processivity of RNA synthesis. The Gre factors insert the extended alpha-helical coiled-coil domains into the RNA polymerase secondary channel to position two invariant acidic residues at the coiled-coil tip near the active site to stabilize the catalytic metal ion. Gfh1, a GreA homolog from Thermus thermophilus, inhibits rather than activates RNA cleavage. Here we report the structure of the T. thermophilus Gfh1 at 2.4 A resolution revealing a two-domain architecture closely resembling that of GreA. However, the interdomain orientation is strikingly distinct (approximately 162 degrees rotation) between the two proteins. In contrast to GreA, which has two acidic residues on a well fixed self-stabilized alpha-turn, the tip of the Gfh1 coiled-coil is flexible and contains four acidic residues. This difference is likely the key to the Gre functional diversity, while Gfh1 inhibits exo- and endonucleolytic cleavage, RNA synthesis, and pyrophosphorolysis, GreA enhances only the endonucleolytic cleavage. We propose that Gfh1 acidic residues stabilize the RNA polymerase active center in a catalytically inactive configuration through Mg2+-mediated interactions. The excess of the acidic residues and inherent flexibility of the coiled-coil tip might allow Gfh1 to adjust its activity to structurally distinct substrates, thereby inhibiting diverse catalytic reactions of RNA polymerase.
About this Structure
2EUL is a Single protein structure of sequence from Thermus thermophilus with as ligand. Full crystallographic information is available from OCA.
Reference
Regulation through the RNA polymerase secondary channel. Structural and functional variability of the coiled-coil transcription factors., Symersky J, Perederina A, Vassylyeva MN, Svetlov V, Artsimovitch I, Vassylyev DG, J Biol Chem. 2006 Jan 20;281(3):1309-12. Epub 2005 Nov 18. PMID:16298991
Page seeded by OCA on Thu Feb 21 17:14:39 2008
Categories: Single protein | Thermus thermophilus | Artsimovitch, I. | Perederina, A. | RSGI, RIKEN Structural Genomics/Proteomics Initiative. | Svetlov, V. | Symersky, J. | Vassylyev, D G. | Vassylyeva, M N. | ZN | Gfh1 | Riken structural genomics/proteomics initiative | Rna polymerase | Rsgi | Structural genomics | Transcription factor
