1ypv: Difference between revisions

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

Human thymidylate synthase, a target in cancer chemotherapy, was crystallized from PEG 3350 with 30 mM ammonium sulfate (AS) in the crystallization medium. The crystals are isomorphous with the high-salt crystals ( approximately 2.0 M AS) and the structure has been solved and refined (R = 22.6%, R(free) = 24.3%) at 1.8 A resolution. The high- and low-AS-concentration structures are quite similar, with loop 181-197 is in the inactive conformation. Also, residues 95-106 and 129-135 (eukaryotic inserts region) show high mobility as assessed by poor electron density and high values of crystallographic temperature factors (residues 1-25 and 108-129 are disordered in both structures). The high mobility of this region may reflect the situation at physiological ionic strength. Of the four sulfate ions observed bound at 2.0 M AS, only two are present at 30 mM AS. The inactive conformation appears to be stabilized by the side chain of Val3 or a leucine residue from the disordered regions. The low-salt conditions of these crystals should be much more suitable for the study of thymidylate synthase inhibitors, especially those that utilize sulfate-binding sites to stabilize the inactive conformation of loop 181-197.

1YPV is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=PO4:'>PO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Thymidylate_synthase Thymidylate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.45 2.1.1.45] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YPV OCA].  

[[Category: Lovelace, L L.]]

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