View source for 1qfe

[[Image:1qfe.jpg|left|200px]]<br /><applet load="1qfe" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="1qfe, resolution 2.1&Aring;" />
'''THE STRUCTURE OF TYPE I 3-DEHYDROQUINATE DEHYDRATASE FROM SALMONELLA TYPHI'''<br />

==Overview==
The structures of enzymes catalyzing the reactions in central metabolic pathways are generally well conserved as are their catalytic mechanisms. The two types of 3-dehydroquinate dehydratase (DHQase) are therefore most unusual since they are unrelated at the sequence level and they utilize completely different mechanisms to catalyze the same overall reaction. The type I enzymes catalyze a cis-dehydration of 3-dehydroquinate via a covalent imine intermediate, while the type II enzymes catalyze a trans-dehydration via an enolate intermediate. Here we report the three-dimensional structures of a representative member of each type of biosynthetic DHQase. Both enzymes function as part of the shikimate pathway, which is essential in microorganisms and plants for the biosynthesis of aromatic compounds including folate, ubiquinone and the aromatic amino acids. An explanation for the presence of two different enzymes catalyzing the same reaction is presented. The absence of the shikimate pathway in animals makes it an attractive target for antimicrobial agents. The availability of these two structures opens the way for the design of highly specific enzyme inhibitors with potential importance as selective therapeutic agents.

==About this Structure==
1QFE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhi Salmonella typhi] with <scene name='pdbligand=DHS:'>DHS</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/3-dehydroquinate_dehydratase 3-dehydroquinate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.10 4.2.1.10] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QFE OCA]. 

==Reference==
The two types of 3-dehydroquinase have distinct structures but catalyze the same overall reaction., Gourley DG, Shrive AK, Polikarpov I, Krell T, Coggins JR, Hawkins AR, Isaacs NW, Sawyer L, Nat Struct Biol. 1999 Jun;6(6):521-5. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10360352 10360352]
[[Category: 3-dehydroquinate dehydratase]]
[[Category: Salmonella typhi]]
[[Category: Single protein]]
[[Category: Coggins, J R.]]
[[Category: Hawkins, A R.]]
[[Category: Polikarpov, I.]]
[[Category: Sawyer, L.]]
[[Category: Shrive, A K.]]
[[Category: DHS]]
[[Category: 3rd enzyme in the shikimate pathway]]
[[Category: conversion of 3-dehydroquinate to dehydroshikimate]]
[[Category: dehydratase]]
[[Category: tim barrel]]

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