View source for 1atg

[[Image:1atg.gif|left|200px]]<br />
<applet load="1atg" size="450" color="white" frame="true" align="right" spinBox="true" 
caption="1atg, resolution 1.2&Aring;" />
'''AZOTOBACTER VINELANDII PERIPLASMIC MOLYBDATE-BINDING PROTEIN'''<br />

==Overview==
Background:. Periplasmic receptors constitute a diverse class of binding, proteins that differ widely in size, sequence and ligand specificity., Nevertheless, almost all of them display a common beta/alpha folding motif, and have similar tertiary structures consisting of two globular domains., The ligand is bound at the bottom of a deep cleft, which lies at the, interface between these two domains. The oxyanion-binding proteins are, notable in that they can discriminate between very similar ligands., Results:. Azotobacter vinelandii is unusual in that it possesses two, periplasmic molybdate-binding proteins. The crystal structure of one of, these with bound ligand has been determined at 1.2 A resolution. It, superficially resembles the structure of sulphate-binding protein (SBP), from Salmonella typhimurium and uses a similar constellation of, hydrogen-bonding interactions to bind its ligand. However, the detailed, interactions are distinct from those of SBP and the more closely related, molybdate-binding protein of Escherichia coli. Conclusions:. Despite, differences in the residues involved in binding, the volumes of the, binding pockets in the A. vinelandii and E. coli molybdate-binding, proteins are similar and are significantly larger than that of SBP. We, conclude that the discrimination between molybdate and sulphate shown by, these binding proteins is largely dependent upon small differences in the, sizes of these two oxyanions.

==About this Structure==
1ATG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii] with WO4, ACT, SO4 and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: MOB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1ATG OCA]. 

==Reference==
Ligand size is a major determinant of specificity in periplasmic oxyanion-binding proteins: the 1.2 A resolution crystal structure of Azotobacter vinelandii ModA., Lawson DM, Williams CE, Mitchenall LA, Pau RN, Structure. 1998 Dec 15;6(12):1529-39. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9862806 9862806]
[[Category: Azotobacter vinelandii]]
[[Category: Single protein]]
[[Category: Lawson, D.M.]]
[[Category: Mitchenall, L.A.]]
[[Category: Pau, R.N.]]
[[Category: Williams, C.E.M.]]
[[Category: ACT]]
[[Category: EDO]]
[[Category: SO4]]
[[Category: WO4]]
[[Category: abc transporter]]
[[Category: binding protein]]
[[Category: molybdate]]
[[Category: periplasm]]
[[Category: tungstate]]

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