1ua1
From Proteopedia
(New page: 200px<br /><applet load="1ua1" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ua1, resolution 2.00Å" /> '''Structure of aminofl...) |
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| - | [[Image:1ua1.gif|left|200px]]<br /><applet load="1ua1" size=" | + | [[Image:1ua1.gif|left|200px]]<br /><applet load="1ua1" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ua1, resolution 2.00Å" /> | caption="1ua1, resolution 2.00Å" /> | ||
'''Structure of aminofluorene adduct paired opposite cytosine at the polymerase active site.'''<br /> | '''Structure of aminofluorene adduct paired opposite cytosine at the polymerase active site.'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Aromatic amines have been studied for more than a half-century as model | + | Aromatic amines have been studied for more than a half-century as model carcinogens representing a class of chemicals that form bulky adducts to the C8 position of guanine in DNA. Among these guanine adducts, the N-(2'-deoxyguanosin-8-yl)-aminofluorene (G-AF) and N-2-(2'-deoxyguanosin-8-yl)-acetylaminofluorene (G-AAF) derivatives are the best studied. Although G-AF and G-AAF differ by only an acetyl group, they exert different effects on DNA replication by replicative and high-fidelity DNA polymerases. Translesion synthesis of G-AF is achieved with high-fidelity polymerases, whereas replication of G-AAF requires specialized bypass polymerases. Here we have presented structures of G-AF as it undergoes one round of accurate replication by a high-fidelity DNA polymerase. Nucleotide incorporation opposite G-AF is achieved in solution and in the crystal, revealing how the polymerase accommodates and replicates past G-AF, but not G-AAF. Like an unmodified guanine, G-AF adopts a conformation that allows it to form Watson-Crick hydrogen bonds with an opposing cytosine that results in protrusion of the bulky fluorene moiety into the major groove. Although incorporation opposite G-AF is observed, the C:G-AF base pair induces distortions to the polymerase active site that slow translesion synthesis. |
==About this Structure== | ==About this Structure== | ||
| - | 1UA1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus] with SO4 and AF as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] Full crystallographic information is available from [http:// | + | 1UA1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=AF:'>AF</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UA1 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Geobacillus stearothermophilus]] | [[Category: Geobacillus stearothermophilus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Becherel, O | + | [[Category: Becherel, O J.]] |
| - | [[Category: Beese, L | + | [[Category: Beese, L S.]] |
| - | [[Category: Fuchs, R | + | [[Category: Fuchs, R P.P.]] |
| - | [[Category: Hsu, G | + | [[Category: Hsu, G W.]] |
| - | [[Category: Kiefer, J | + | [[Category: Kiefer, J R.]] |
[[Category: AF]] | [[Category: AF]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
[[Category: dna polymerase i; dna replication; klenow fragment; protein-dna complex; aminofluorene; aromatic amine; dna lesion; translation replication]] | [[Category: dna polymerase i; dna replication; klenow fragment; protein-dna complex; aminofluorene; aromatic amine; dna lesion; translation replication]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:22:12 2008'' |
Revision as of 13:22, 21 February 2008
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Structure of aminofluorene adduct paired opposite cytosine at the polymerase active site.
Overview
Aromatic amines have been studied for more than a half-century as model carcinogens representing a class of chemicals that form bulky adducts to the C8 position of guanine in DNA. Among these guanine adducts, the N-(2'-deoxyguanosin-8-yl)-aminofluorene (G-AF) and N-2-(2'-deoxyguanosin-8-yl)-acetylaminofluorene (G-AAF) derivatives are the best studied. Although G-AF and G-AAF differ by only an acetyl group, they exert different effects on DNA replication by replicative and high-fidelity DNA polymerases. Translesion synthesis of G-AF is achieved with high-fidelity polymerases, whereas replication of G-AAF requires specialized bypass polymerases. Here we have presented structures of G-AF as it undergoes one round of accurate replication by a high-fidelity DNA polymerase. Nucleotide incorporation opposite G-AF is achieved in solution and in the crystal, revealing how the polymerase accommodates and replicates past G-AF, but not G-AAF. Like an unmodified guanine, G-AF adopts a conformation that allows it to form Watson-Crick hydrogen bonds with an opposing cytosine that results in protrusion of the bulky fluorene moiety into the major groove. Although incorporation opposite G-AF is observed, the C:G-AF base pair induces distortions to the polymerase active site that slow translesion synthesis.
About this Structure
1UA1 is a Protein complex structure of sequences from Geobacillus stearothermophilus with and as ligands. Active as DNA-directed DNA polymerase, with EC number 2.7.7.7 Full crystallographic information is available from OCA.
Reference
Observing translesion synthesis of an aromatic amine DNA adduct by a high-fidelity DNA polymerase., Hsu GW, Kiefer JR, Burnouf D, Becherel OJ, Fuchs RP, Beese LS, J Biol Chem. 2004 Nov 26;279(48):50280-5. Epub 2004 Sep 22. PMID:15385534
Page seeded by OCA on Thu Feb 21 15:22:12 2008
Categories: DNA-directed DNA polymerase | Geobacillus stearothermophilus | Protein complex | Becherel, O J. | Beese, L S. | Fuchs, R P.P. | Hsu, G W. | Kiefer, J R. | AF | SO4 | Dna polymerase i; dna replication; klenow fragment; protein-dna complex; aminofluorene; aromatic amine; dna lesion; translation replication
