2nqh
From Proteopedia
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'''High Resolution crystal structure of Escherichia coli endonuclease IV (Endo IV) E261Q mutant''' | '''High Resolution crystal structure of Escherichia coli endonuclease IV (Endo IV) E261Q mutant''' | ||
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| + | ==Overview== | ||
| + | Escherichia coli endonuclease IV is an archetype for an abasic or apurinic-apyrimidinic endonuclease superfamily crucial for DNA base excision repair. Here biochemical, mutational and crystallographic characterizations reveal a three-metal ion mechanism for damage binding and incision. The 1.10-A resolution DNA-free and the 2.45-A resolution DNA-substrate complex structures capture substrate stabilization by Arg37 and reveal a distorted Zn(3)-ligand arrangement that reverts, after catalysis, to an ideal geometry suitable to hold rather than release cleaved DNA product. The 1.45-A resolution DNA-product complex structure shows how Tyr72 caps the active site, tunes its dielectric environment and promotes catalysis by Glu261-activated hydroxide, bound to two Zn(2+) ions throughout catalysis. These structural, mutagenesis and biochemical results suggest general requirements for abasic site removal in contrast to features specific to the distinct endonuclease IV alpha-beta triose phosphate isomerase (TIM) barrel and APE1 four-layer alpha-beta folds of the apurinic-apyrimidinic endonuclease families. | ||
==About this Structure== | ==About this Structure== | ||
2NQH 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=2NQH OCA]. | 2NQH 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=2NQH OCA]. | ||
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| + | ==Reference== | ||
| + | DNA apurinic-apyrimidinic site binding and excision by endonuclease IV., Garcin ED, Hosfield DJ, Desai SA, Haas BJ, Bjoras M, Cunningham RP, Tainer JA, Nat Struct Mol Biol. 2008 Apr 13;. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/18408731 18408731] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: Hosfield, D J.]] | [[Category: Hosfield, D J.]] | ||
[[Category: Tainer, J A.]] | [[Category: Tainer, J A.]] | ||
| - | [[Category: | + | [[Category: Hydrolase]] |
| - | [[Category: | + | [[Category: Tim-barrel]] |
| - | [[Category: | + | [[Category: Trinuclear zinc center]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Apr 24 09:25:19 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 06:25, 24 April 2008
High Resolution crystal structure of Escherichia coli endonuclease IV (Endo IV) E261Q mutant
Overview
Escherichia coli endonuclease IV is an archetype for an abasic or apurinic-apyrimidinic endonuclease superfamily crucial for DNA base excision repair. Here biochemical, mutational and crystallographic characterizations reveal a three-metal ion mechanism for damage binding and incision. The 1.10-A resolution DNA-free and the 2.45-A resolution DNA-substrate complex structures capture substrate stabilization by Arg37 and reveal a distorted Zn(3)-ligand arrangement that reverts, after catalysis, to an ideal geometry suitable to hold rather than release cleaved DNA product. The 1.45-A resolution DNA-product complex structure shows how Tyr72 caps the active site, tunes its dielectric environment and promotes catalysis by Glu261-activated hydroxide, bound to two Zn(2+) ions throughout catalysis. These structural, mutagenesis and biochemical results suggest general requirements for abasic site removal in contrast to features specific to the distinct endonuclease IV alpha-beta triose phosphate isomerase (TIM) barrel and APE1 four-layer alpha-beta folds of the apurinic-apyrimidinic endonuclease families.
About this Structure
2NQH is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
DNA apurinic-apyrimidinic site binding and excision by endonuclease IV., Garcin ED, Hosfield DJ, Desai SA, Haas BJ, Bjoras M, Cunningham RP, Tainer JA, Nat Struct Mol Biol. 2008 Apr 13;. PMID:18408731 Page seeded by OCA on Thu Apr 24 09:25:19 2008
