1qyp
From Proteopedia
(New page: 200px<br /><applet load="1qyp" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qyp" /> '''THERMOCOCCUS CELER RPB9, NMR, 25 STRUCTURES'...) |
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| - | [[Image:1qyp.jpg|left|200px]]<br /><applet load="1qyp" size=" | + | [[Image:1qyp.jpg|left|200px]]<br /><applet load="1qyp" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qyp" /> | caption="1qyp" /> | ||
'''THERMOCOCCUS CELER RPB9, NMR, 25 STRUCTURES'''<br /> | '''THERMOCOCCUS CELER RPB9, NMR, 25 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Transcriptional initiation and elongation provide control | + | BACKGROUND: Transcriptional initiation and elongation provide control points in gene expression. Eukaryotic RNA polymerase II subunit 9 (RPB9) regulates start-site selection and elongational arrest. RPB9 contains Cys4 Zn(2+)-binding motifs which are conserved in archaea and homologous to those of the general transcription factors TFIIB and TFIIS. RESULTS: The structure of an RPB9 domain from the hyperthermophilic archaeon Thermococcus celer was determined at high resolution by NMR spectroscopy. The structure consists of an apical tetrahedral Zn(2+)-binding site, central beta sheet and disordered loop. Although the structure lacks a globular hydrophobic core, the two surfaces of the beta sheet each contain well ordered aromatic rings engaged in serial edge-to-face interactions. Basic sidechains are clustered near the Zn(2+)-binding site. The disordered loop contains sidechains conserved in TFIIS, including acidic residues essential for the stimulation of transcriptional elongation. CONCLUSIONS: The planar architecture of the RPB9 zinc ribbon-distinct from that of a conventional globular domain-can accommodate significant differences in the alignment of polar, non-polar and charged sidechains. Such divergence is associated with local and non-local changes in structure. The RPB9 structure is distinguished by a fourth beta strand (extending the central beta sheet) in a well ordered N-terminal segment and also differs from TFIIS (but not TFIIB) in the orientation of its apical Zn(2+)-binding site. Cys4 Zn(2+)-binding sites with distinct patterns of polar, non-polar and charged residues are conserved among unrelated RNAP subunits and predicted to form variant zinc ribbons. |
==About this Structure== | ==About this Structure== | ||
| - | 1QYP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermococcus_celer Thermococcus celer] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1QYP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermococcus_celer Thermococcus celer] 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=1QYP OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Thermococcus celer]] | [[Category: Thermococcus celer]] | ||
| - | [[Category: Jones, D | + | [[Category: Jones, D N.M.]] |
| - | [[Category: Kaine, B | + | [[Category: Kaine, B P.]] |
[[Category: Wang, B.]] | [[Category: Wang, B.]] | ||
| - | [[Category: Weiss, M | + | [[Category: Weiss, M A.]] |
[[Category: ZN]] | [[Category: ZN]] | ||
[[Category: extremophile]] | [[Category: extremophile]] | ||
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[[Category: zn ribbon]] | [[Category: zn ribbon]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:45:14 2008'' |
Revision as of 12:45, 21 February 2008
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THERMOCOCCUS CELER RPB9, NMR, 25 STRUCTURES
Overview
BACKGROUND: Transcriptional initiation and elongation provide control points in gene expression. Eukaryotic RNA polymerase II subunit 9 (RPB9) regulates start-site selection and elongational arrest. RPB9 contains Cys4 Zn(2+)-binding motifs which are conserved in archaea and homologous to those of the general transcription factors TFIIB and TFIIS. RESULTS: The structure of an RPB9 domain from the hyperthermophilic archaeon Thermococcus celer was determined at high resolution by NMR spectroscopy. The structure consists of an apical tetrahedral Zn(2+)-binding site, central beta sheet and disordered loop. Although the structure lacks a globular hydrophobic core, the two surfaces of the beta sheet each contain well ordered aromatic rings engaged in serial edge-to-face interactions. Basic sidechains are clustered near the Zn(2+)-binding site. The disordered loop contains sidechains conserved in TFIIS, including acidic residues essential for the stimulation of transcriptional elongation. CONCLUSIONS: The planar architecture of the RPB9 zinc ribbon-distinct from that of a conventional globular domain-can accommodate significant differences in the alignment of polar, non-polar and charged sidechains. Such divergence is associated with local and non-local changes in structure. The RPB9 structure is distinguished by a fourth beta strand (extending the central beta sheet) in a well ordered N-terminal segment and also differs from TFIIS (but not TFIIB) in the orientation of its apical Zn(2+)-binding site. Cys4 Zn(2+)-binding sites with distinct patterns of polar, non-polar and charged residues are conserved among unrelated RNAP subunits and predicted to form variant zinc ribbons.
About this Structure
1QYP is a Single protein structure of sequence from Thermococcus celer with as ligand. Full crystallographic information is available from OCA.
Reference
High-resolution structure of an archaeal zinc ribbon defines a general architectural motif in eukaryotic RNA polymerases., Wang B, Jones DN, Kaine BP, Weiss MA, Structure. 1998 May 15;6(5):555-69. PMID:9634694
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