2std: Difference between revisions

[[Image:2std.gif|left|200px]]<br /><applet load="2std" size="350" color="white" frame="true" align="right" spinBox="true"  

Scytalone dehydratase is a member of the group of enzymes involved in fungal melanin biosynthesis in a phytopathogenic fungus, Pyricularia oryzae, which causes rice blast disease. Carpropamid [(1RS,3SR)-2, 2-dichloro-N-[(R)-1-(4-chlorophenyl)ethyl]-1-ethyl-3-methylcyclopropa necarboxamide] is a tight-binding inhibitor of the enzyme. To clarify the structural basis for tight-binding inhibition, the crystal structure of the enzyme complexed with carpropamid was analyzed using diffraction data collected at 100 K. The structural model was refined to a crystallographic R-factor of 0.180 against reflections up to a resolution of 2.1 A. Carpropamid was bound in a hydrophobic cavity of the enzyme. Three types of interactions appeared to contribute to the binding. (i) A hydrogen bond was formed between a chloride atom in the dichloromethylethylcyclopropane ring of carpropamid and Asn-131 of the enzyme. (ii) The (chlorophenyl)ethyl group of carpropamid built strong contacts with Val-75, and this group further formed a cluster of aromatic rings together with four aromatic residues in the enzyme (Tyr-50, Phe-53, Phe-158, and Phe-162). (iii) Two hydration water molecules bound to the carboxamide group of carpropamid, and they were further hydrogen-bonded to Tyr-30, Tyr-50, His-85, and His-110. As a result of interactions between carpropamid and the phenylalanine residues (Phe-158 and Phe-162) in the C-terminal region of the enzyme, the C-terminal region completely covered the inhibitor, ensuring its localization in the cavity.

2STD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Magnaporthe_grisea Magnaporthe grisea] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=CRP:'>CRP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Scytalone_dehydratase Scytalone dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.94 4.2.1.94] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2STD OCA].  

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