1g15
From Proteopedia
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|PDB= 1g15 |SIZE=350|CAPTION= <scene name='initialview01'>1g15</scene>, resolution 1.9Å | |PDB= 1g15 |SIZE=350|CAPTION= <scene name='initialview01'>1g15</scene>, resolution 1.9Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=MN:MANGANESE (II) ION'>MN</scene> | + | |LIGAND= <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Ribonuclease_H Ribonuclease H], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.26.4 3.1.26.4] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Ribonuclease_H Ribonuclease H], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.26.4 3.1.26.4] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1g15 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g15 OCA], [http://www.ebi.ac.uk/pdbsum/1g15 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1g15 RCSB]</span> | ||
}} | }} | ||
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[[Category: Goedken, E R.]] | [[Category: Goedken, E R.]] | ||
[[Category: Marqusee, S.]] | [[Category: Marqusee, S.]] | ||
| - | [[Category: MN]] | ||
[[Category: activation/attenuation mechanism]] | [[Category: activation/attenuation mechanism]] | ||
[[Category: divalent metal binding]] | [[Category: divalent metal binding]] | ||
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[[Category: rnase h]] | [[Category: rnase h]] | ||
| - | ''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 20:34:21 2008'' |
Revision as of 17:34, 30 March 2008
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| , resolution 1.9Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Activity: | Ribonuclease H, with EC number 3.1.26.4 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CO-CRYSTAL OF E. COLI RNASE HI WITH TWO MN2+ IONS BOUND IN THE THE ACTIVE SITE
Overview
Ribonuclease H (RNase H) selectively degrades the RNA strand of RNA.DNA hybrids in a divalent cation-dependent manner. Previous structural studies revealed a single Mg(2+) ion-binding site in Escherichia coli RNase HI. In the crystal structure of the related RNase H domain of human immunodeficiency virus reverse transcriptase, however, two Mn(2+) ions were observed suggesting a different mode of metal binding. E. coli RNase HI shows catalytic activity in the presence of Mg(2+) or Mn(2+) ions, but these two metals show strikingly different optimal concentrations. Mg(2+) ions are required in millimolar concentrations, but Mn(2+) ions are only required in micromolar quantities. Based upon the metal dependence of E. coli RNase HI activity, we proposed an activation/attenuation model in which one metal is required for catalysis, and binding of a second metal is inhibitory. We have now solved the co-crystal structure of E. coli RNase HI with Mn(2+) ions at 1.9-A resolution. Two octahedrally coordinated Mn(2+) ions are seen to bind to the enzyme-active site. Residues Asp-10, Glu-48, and Asp-70 make direct (inner sphere) coordination contacts to the first (activating) metal, whereas residues Asp-10 and Asp-134 make direct contacts to the second (attenuating) metal. This structure is consistent with biochemical evidence suggesting that two metal ions may bind RNase H but liganding a second ion inhibits RNase H activity.
About this Structure
1G15 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Co-crystal of Escherichia coli RNase HI with Mn2+ ions reveals two divalent metals bound in the active site., Goedken ER, Marqusee S, J Biol Chem. 2001 Mar 9;276(10):7266-71. Epub 2000 Nov 16. PMID:11083878
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