1qnt: Difference between revisions

Revision as of 06:29, 3 May 2008

X-RAY STRUCTURE OF HUMAN O6ALKYLGUANINE-DNA ALKYLTRANSFERASE

OverviewOverview

The mutagenic and carcinogenic effects of simple alkylating agents are mainly due to O(6)-alkylation of guanine in DNA. This lesion results in transition mutations. In both prokaryotic and eukaryotic cells, repair is effected by direct reversal of the damage by a suicide protein, O(6)-alkylguanine-DNA alkyltransferase. The alkyltransferase removes the alkyl group to one of its own cysteine residues. However, this mechanism for preserving genomic integrity limits the effectiveness of certain alkylating anticancer agents. A high level of the alkyltransferase in many tumour cells renders them resistant to such drugs. Here we report the X-ray structure of the human alkyltransferase solved using the technique of multiple wavelength anomalous dispersion. This structure explains the markedly different specificities towards various O(6)-alkyl lesions and inhibitors when compared with the Escherichia coli protein (for which the structure has already been determined). It is also used to interpret the behaviour of certain mutant alkyltransferases to enhance biochemical understanding of the protein. Further examination of the various models proposed for DNA binding is also permitted. This structure may be useful for the design and refinement of drugs as chemoenhancers of alkylating agent chemotherapy.

About this StructureAbout this Structure

1QNT is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of the human O(6)-alkylguanine-DNA alkyltransferase., Wibley JE, Pegg AE, Moody PC, Nucleic Acids Res. 2000 Jan 15;28(2):393-401. PMID:10606635 Page seeded by OCA on Sat May 3 06:29:52 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1qnt.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 1qnt |SIZE=350|CAPTION= <scene name='initialview01'>1qnt</scene>, resolution 1.90&Aring;
+The line below this paragraph, containing "STRUCTURE_1qnt", creates the "Structure Box" on the page.
-|SITE= <scene name='pdbsite=ACC:Alkyl+Acceptor'>ACC</scene>
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND=
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Methylated-DNA--[protein]-cysteine_S-methyltransferase Methylated-DNA--[protein]-cysteine S-methyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.63 2.1.1.63] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1qnt|  PDB=1qnt  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1qnt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qnt OCA], [http://www.ebi.ac.uk/pdbsum/1qnt PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1qnt RCSB]</span>
-}}
 '''X-RAY STRUCTURE OF HUMAN O6ALKYLGUANINE-DNA ALKYLTRANSFERASE'''
@@ Line 24: / Line 21: @@
 Crystal structure of the human O(6)-alkylguanine-DNA alkyltransferase., Wibley JE, Pegg AE, Moody PC, Nucleic Acids Res. 2000 Jan 15;28(2):393-401. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10606635 10606635]
 [[Category: Homo sapiens]]
-[[Category: Methylated-DNA--[protein]-cysteine S-methyltransferase]]
 [[Category: Single protein]]
 [[Category: Moody, P C.E.]]
 [[Category: Wibley, J E.A.]]
-[[Category: alkyltransferase]]
+[[Category: Alkyltransferase]]
-[[Category: dna repair]]
+[[Category: Dna repair]]
-[[Category: methyltransferase]]
+[[Category: Methyltransferase]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 06:29:52 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:16:26 2008''