1t6d: Difference between revisions

[[Image:1t6d.jpg|left|200px]]<br /><applet load="1t6d" size="350" color="white" frame="true" align="right" spinBox="true"  

Exopolyphosphatase/guanosine pentaphosphate phosphohydrolase (PPX/GPPA) enzymes play central roles in the bacterial stringent response induced by starvation. The high-resolution crystal structure of the putative Aquifex aeolicus PPX/GPPA phosphatase from the actin-like ATPase domain superfamily has been determined, providing the first insights to features of the common catalytic core of the PPX/GPPA family. The protein has a two-domain structure with an active site located in the interdomain cleft. Two crystal forms were investigated (type I and II) at resolutions of 1.53 and 2.15 A, respectively. This revealed a structural flexibility that has previously been described as a "butterfly-like" cleft opening around the active site in other actin-like superfamily proteins. A calcium ion is observed at the center of this region in type I crystals, substantiating that PPX/GPPA enzymes use metal ions for catalysis. Structural analysis suggests that nucleotides bind at a similar position to that seen in other members of the superfamily.

1T6D is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aquifex_aeolicus_vf5 Aquifex aeolicus vf5] with <scene name='pdbligand=CL:'>CL</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T6D OCA].  

[[Category: Kastrup, J S.]]

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