1ea4
From Proteopedia
| Line 4: | Line 4: | ||
|PDB= 1ea4 |SIZE=350|CAPTION= <scene name='initialview01'>1ea4</scene>, resolution 2.95Å | |PDB= 1ea4 |SIZE=350|CAPTION= <scene name='initialview01'>1ea4</scene>, resolution 2.95Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= | + | |LIGAND= <scene name='pdbligand=DA:2'-DEOXYADENOSINE-5'-MONOPHOSPHATE'>DA</scene>, <scene name='pdbligand=DC:2'-DEOXYCYTIDINE-5'-MONOPHOSPHATE'>DC</scene>, <scene name='pdbligand=DG:2'-DEOXYGUANOSINE-5'-MONOPHOSPHATE'>DG</scene>, <scene name='pdbligand=DT:THYMIDINE-5'-MONOPHOSPHATE'>DT</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ea4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ea4 OCA], [http://www.ebi.ac.uk/pdbsum/1ea4 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ea4 RCSB]</span> | ||
}} | }} | ||
| Line 16: | Line 19: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1EA4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/ | + | 1EA4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus Streptococcus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EA4 OCA]. |
==Reference== | ==Reference== | ||
Plasmid transcriptional repressor CopG oligomerises to render helical superstructures unbound and in complexes with oligonucleotides., Costa M, Sola M, del Solar G, Eritja R, Hernandez-Arriaga AM, Espinosa M, Gomis-Ruth FX, Coll M, J Mol Biol. 2001 Jul 6;310(2):403-17. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11428897 11428897] | Plasmid transcriptional repressor CopG oligomerises to render helical superstructures unbound and in complexes with oligonucleotides., Costa M, Sola M, del Solar G, Eritja R, Hernandez-Arriaga AM, Espinosa M, Gomis-Ruth FX, Coll M, J Mol Biol. 2001 Jul 6;310(2):403-17. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11428897 11428897] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: | + | [[Category: Streptococcus]] |
[[Category: Acebo, P.]] | [[Category: Acebo, P.]] | ||
[[Category: Coll, M.]] | [[Category: Coll, M.]] | ||
| Line 36: | Line 39: | ||
[[Category: transcriptional repressor]] | [[Category: transcriptional repressor]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:58:24 2008'' |
Revision as of 16:58, 30 March 2008
| |||||||
| , resolution 2.95Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
TRANSCRIPTIONAL REPRESSOR COPG/22BP DSDNA COMPLEX
Overview
CopG is a 45 amino acid residue transcriptional repressor involved in the copy number control of the streptococcal plasmid pMV158. To do so, it binds to a DNA operator that contains a 13 bp pseudosymmetric DNA element. Binding of CopG to its operator results in repression, at the transcriptional level, of its own synthesis and that of the initiator of replication protein, RepB. Biochemical experiments have shown that CopG co-operatively associates to its target DNA at low protein:DNA ratios, completely protecting four helical turns on the same face of the double helix in both directions from the inverted repeat that constitutes the CopG primary target. This has been correlated with a CopG-mediated DNA bend of about 100 degrees. Here, we show that binding of CopG to DNA fragments containing the inverted repeat just at one end led to nucleation of the protein initiating from the inverted repeat. Nucleation extended to the entire fragment, with CopG-DNA contacts occurring on the same face of the DNA helix. The protein, the prototype for a family of homologous plasmid repressors, displays a homodimeric ribbon-helix-helix arrangement. It polymerises within the unbound crystal to render a continuous right-handed protein superhelix of homodimers, around which a bound double-stranded (ds) DNA could wrap. We have solved the crystal structure of CopG in complex with a 22 bp dsDNA oligonucleotide encompassing the cognate pseudosymmetric element. In the crystal, one protein tetramer binds at one face of the DNA with two parallel beta-ribbons inserted into the major groove. The DNA is bent about 50 degrees under compression of both major and minor grooves. A continuous right-handed complex helix made up mainly by protein-protein and some protein-DNA interactions is observed. The protein-protein interactions involve regions similar to those observed in the oligomerisation of the native crystals and those employed to set up the functional tetramer. A previously solved complex structure of the protein with a 19 bp dsDNA had unveiled a left-handed helical superstructure just made up by DNA interactions.
About this Structure
1EA4 is a Single protein structure of sequence from Streptococcus. Full crystallographic information is available from OCA.
Reference
Plasmid transcriptional repressor CopG oligomerises to render helical superstructures unbound and in complexes with oligonucleotides., Costa M, Sola M, del Solar G, Eritja R, Hernandez-Arriaga AM, Espinosa M, Gomis-Ruth FX, Coll M, J Mol Biol. 2001 Jul 6;310(2):403-17. PMID:11428897
Page seeded by OCA on Sun Mar 30 19:58:24 2008
