1mpg: Difference between revisions

[[Image:1mpg.gif|left|200px]]<br /><applet load="1mpg" size="350" color="white" frame="true" align="right" spinBox="true"  

Base-excision DNA repair proteins that target alkylation damage act on a variety of seemingly dissimilar adducts, yet fail to recognize other closely related lesions. The 1.8 A crystal structure of the monofunctional DNA glycosylase AlkA (E. coli 3-methyladenine-DNA glycosylase II) reveals a large hydrophobic cleft unusually rich in aromatic residues. An Asp residue projecting into this cleft is essential for catalysis, and it governs binding specificity for mechanism-based inhibitors. We propose that AlkA recognizes electron-deficient methylated bases through pi-donor/acceptor interactions involving the electron-rich aromatic cleft. Remarkably, AlkA is similar in fold and active site location to the bifunctional glycosylase/lyase endonuclease III, suggesting the two may employ fundamentally related mechanisms for base excision.

1MPG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/DNA-3-methyladenine_glycosylase_II DNA-3-methyladenine glycosylase II], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.21 3.2.2.21] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MPG OCA].  

[[Category: Ellenberger, T E.]]

[[Category: Schaerer, O D.]]

[[Category: Verdine, G L.]]

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