1cez: Difference between revisions
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[[Image:1cez.gif|left|200px]] | [[Image:1cez.gif|left|200px]] | ||
'''CRYSTAL STRUCTURE OF A T7 RNA POLYMERASE-T7 PROMOTER COMPLEX''' | {{Structure | ||
|PDB= 1cez |SIZE=350|CAPTION= <scene name='initialview01'>1cez</scene>, resolution 2.40Å | |||
|SITE= | |||
|LIGAND= | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/DNA-directed_RNA_polymerase DNA-directed RNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.6 2.7.7.6] | |||
|GENE= | |||
}} | |||
'''CRYSTAL STRUCTURE OF A T7 RNA POLYMERASE-T7 PROMOTER COMPLEX''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1CEZ is a [ | 1CEZ is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t7 Bacteriophage t7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CEZ OCA]. | ||
==Reference== | ==Reference== | ||
Structural basis for initiation of transcription from an RNA polymerase-promoter complex., Cheetham GM, Jeruzalmi D, Steitz TA, Nature. 1999 May 6;399(6731):80-3. PMID:[http:// | Structural basis for initiation of transcription from an RNA polymerase-promoter complex., Cheetham GM, Jeruzalmi D, Steitz TA, Nature. 1999 May 6;399(6731):80-3. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10331394 10331394] | ||
[[Category: Bacteriophage t7]] | [[Category: Bacteriophage t7]] | ||
[[Category: DNA-directed RNA polymerase]] | [[Category: DNA-directed RNA polymerase]] | ||
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[[Category: t7 rna polymerase]] | [[Category: t7 rna polymerase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:23:35 2008'' | ||
Revision as of 08:23, 20 March 2008
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| 1cez, resolution 2.40Å | |||||||||||||
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| Activity: | DNA-directed RNA polymerase, with EC number 2.7.7.6 | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
CRYSTAL STRUCTURE OF A T7 RNA POLYMERASE-T7 PROMOTER COMPLEX
Overview
Although the single-polypeptide-chain RNA polymerase from bacteriophage T7 (T7RNAP), like other RNA polymerases, uses the same mechanism of polymerization as the DNA polymerases, it can also recognize a specific promoter sequence, initiate new RNA chains from a single nucleotide, abortively cycle the synthesis of short transcripts, be regulated by a transcription inhibitor, and terminate transcription. As T7RNAP is homologous to the Pol I family of DNA polymerases, the differences between the structure of T7RNAP complexed to substrates and that of the corresponding DNA polymerase complex provides a structural basis for understanding many of these functional differences. T7RNAP initiates RNA synthesis at promoter sequences that are conserved from positions -17 to +6 relative to the start site of transcription. The crystal structure at 2.4 A resolution of T7RNAP complexed with a 17-base-pair promoter shows that the four base pairs closest to the catalytic active site have melted to form a transcription bubble. The T7 promoter sequence is recognized by interactions in the major groove between an antiparallel beta-loop and bases. The amino-terminal domain is involved in promoter recognition and DNA melting. We have also used homology modelling of the priming and incoming nucleoside triphosphates from the T7 DNA-polymerase ternary complex structure to explain the specificity of T7RNAP for ribonucleotides, its ability to initiate from a single nucleotide, and the abortive cycling at the initiation of transcription.
About this Structure
1CEZ is a Single protein structure of sequence from Bacteriophage t7. Full crystallographic information is available from OCA.
Reference
Structural basis for initiation of transcription from an RNA polymerase-promoter complex., Cheetham GM, Jeruzalmi D, Steitz TA, Nature. 1999 May 6;399(6731):80-3. PMID:10331394
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