1qe0: Difference between revisions

[[Image:1qe0.gif|left|200px]]<br /><applet load="1qe0" size="350" color="white" frame="true" align="right" spinBox="true"  

The crystal structure of the Staphylococcus aureus histidyl-tRNA synthetase apoprotein has been determined at 2.7 A resolution. Several important loops in the active site either become disordered or adopt very different conformations compared to their ligand-bound states. These include the histidine A motif (Arg257-Tyr262) that is essential for substrate recognition, a loop (Gly52-Lys62) that seems to control the communication between the histidine and ATP binding sites, the motif 2 loop (Glu114-Arg120) that binds ATP, and the insertion domain that is likely to bind tRNA. These ligand-induced structural changes are supported by fluorescence experiments, which also suggest highly cooperative dynamics. A dynamic and cooperative active site is most likely necessary for the proper functioning of the histidyl-tRNA synthetase, and suggests a novel mechanism for improving charging fidelity.

1QE0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Active as [http://en.wikipedia.org/wiki/Histidine--tRNA_ligase Histidine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.21 6.1.1.21] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QE0 OCA].  

[[Category: Abdel-Meguid, S S.]]

[[Category: Blackburn, M N.]]

[[Category: Chohan, I K.]]

[[Category: Janson, C A.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:38:39 2008''