1g15: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1g15.jpg|left|200px]] | [[Image:1g15.jpg|left|200px]] | ||
'''CO-CRYSTAL OF E. COLI RNASE HI WITH TWO MN2+ IONS BOUND IN THE THE ACTIVE SITE''' | {{Structure | ||
|PDB= 1g15 |SIZE=350|CAPTION= <scene name='initialview01'>1g15</scene>, resolution 1.9Å | |||
|SITE= | |||
|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] | |||
|GENE= | |||
}} | |||
'''CO-CRYSTAL OF E. COLI RNASE HI WITH TWO MN2+ IONS BOUND IN THE THE ACTIVE SITE''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
1G15 is a [ | 1G15 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G15 OCA]. | ||
==Reference== | ==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:[http:// | 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:[http://www.ncbi.nlm.nih.gov/pubmed/11083878 11083878] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Ribonuclease H]] | [[Category: Ribonuclease H]] | ||
| Line 23: | Line 32: | ||
[[Category: rnase h]] | [[Category: rnase h]] | ||
''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 11:16:45 2008'' | ||
Revision as of 09:16, 20 March 2008
| |||||||||||||
| 1g15, resolution 1.9Å | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ligands: | MN | ||||||||||||
| Activity: | Ribonuclease H, with EC number 3.1.26.4 | ||||||||||||
| 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
Page seeded by OCA on Thu Mar 20 11:16:45 2008
