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2pk2

From Proteopedia

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Revision as of 07:23, 21 August 2019

Cyclin box structure of the P-TEFb subunit Cyclin T1 derived from a fusion complex with EIAV Tat

Structural highlights

2pk2 is a 4 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	1pkw
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[CCNT1_HUMAN] Regulatory subunit of the cyclin-dependent kinase pair (CDK9/cyclin-T1) complex, also called positive transcription elongation factor B (P-TEFb), which is proposed to facilitate the transition from abortive to productive elongation by phosphorylating the CTD (carboxy-terminal domain) of the large subunit of RNA polymerase II (RNA Pol II). In case of HIV or SIV infections, binds to the transactivation domain of the viral nuclear transcriptional activator, Tat, thereby increasing Tat's affinity for the transactivating response RNA element (TAR RNA). Serves as an essential cofactor for Tat, by promoting RNA Pol II activation, allowing transcription of viral genes.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The positive transcription elongation factor b (P-TEFb) is an essential regulator of viral gene expression during the life cycle of human immunodeficiency virus type 1 (HIV-1). Its cyclin T1 subunit forms a ternary complex with the viral transcriptional transactivator (Tat) protein and the transactivation response (TAR) RNA element thereby activating cyclin dependent kinase 9 (Cdk9), which stimulates transcription at the level of chain elongation. We report the structure of the cyclin box domain of human cyclin T1 at a resolution of 2.67 A. The structure was obtained by crystallographic analysis of a fusion protein composed of cyclin T1 linked to the transactivator protein Tat from equine infectious anemia virus (EIAV), which is functionally and structurally related to HIV-1 Tat. The conserved cyclin box domain of cyclin T1 exhibits structural features for interaction with physiological binding partners such as Cdk9. A recognition site for Cdk/Cyclin substrates is partly covered by a cyclin T-specific insert, suggesting specific interactions with regulatory factors. The previously identified Tat/TAR recognition motif (TRM) forms a C-terminal helix that is partly occluded in the cyclin box repeat interface, while cysteine 261 is accessible to form an intermolecular zinc finger with Tat. Residues of the TRM contribute to a positively charged groove that may directly attract RNA molecules. The EIAV Tat protein instead appeared undefined from the electron density map suggesting that it is highly disordered. Functional experiments confirmed the TAR binding properties of the fusion protein and suggested residues on the second cyclin box repeat to contribute to Tat stimulated transcription.

Cyclin box structure of the P-TEFb subunit cyclin T1 derived from a fusion complex with EIAV tat.,Anand K, Schulte A, Fujinaga K, Scheffzek K, Geyer M J Mol Biol. 2007 Jul 27;370(5):826-36. Epub 2007 May 10. PMID:17540406^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Anand K, Schulte A, Fujinaga K, Scheffzek K, Geyer M. Cyclin box structure of the P-TEFb subunit cyclin T1 derived from a fusion complex with EIAV tat. J Mol Biol. 2007 Jul 27;370(5):826-36. Epub 2007 May 10. PMID:17540406 doi:http://dx.doi.org/10.1016/j.jmb.2007.04.077

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2pk2"

@@ Line 1: / Line 1: @@
 ==Cyclin box structure of the P-TEFb subunit Cyclin T1 derived from a fusion complex with EIAV Tat==
-<StructureSection load='2pk2' size='340' side='right' caption='[[2pk2]], [[Resolution|resolution]] 2.67&Aring;' scene=''>
+<StructureSection load='2pk2' size='340' side='right'caption='[[2pk2]], [[Resolution|resolution]] 2.67&Aring;' scene=''>
 == Structural highlights ==
 <table><tr><td colspan='2'>[[2pk2]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PK2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2PK2 FirstGlance]. <br>
@@ Line 13: / Line 13: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pk/2pk2_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pk/2pk2_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
@@ Line 28: / Line 28: @@
 </div>
 <div class="pdbe-citations 2pk2" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[Tat protein|Tat protein]]
 == References ==
 <references/>
@@ Line 33: / Line 36: @@
 </StructureSection>
 [[Category: Human]]
+[[Category: Large Structures]]
 [[Category: Anand, K]]
 [[Category: Fujinaga, K]]

2pk2

From Proteopedia

Revision as of 07:23, 21 August 2019

Cyclin box structure of the P-TEFb subunit Cyclin T1 derived from a fusion complex with EIAV Tat

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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