1jqn: Difference between revisions

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

Phosphoenolpyruvate carboxylase (PEPC) catalyzes the first step in the fixation of atmospheric CO(2) during C(4) photosynthesis. The crystal structure of C(4) form maize PEPC (ZmPEPC), the first structure of the plant PEPCs, has been determined at 3.0 A resolution. The structure includes a sulfate ion at the plausible binding site of an allosteric activator, glucose 6-phosphate. The crystal structure of E. coli PEPC (EcPEPC) complexed with Mn(2+), phosphoenolpyruvate analog (3,3-dichloro-2-dihydroxyphosphinoylmethyl-2-propenoate), and an allosteric inhibitor, aspartate, has also been determined at 2.35 A resolution. Dynamic movements were found in the ZmPEPC structure, compared with the EcPEPC structure, around two loops near the active site. On the basis of these molecular structures, the mechanisms for the carboxylation reaction and for the allosteric regulation of PEPC are proposed.

1JQN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MN:'>MN</scene>, <scene name='pdbligand=ASP:'>ASP</scene> and <scene name='pdbligand=DCO:'>DCO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phosphoenolpyruvate_carboxylase Phosphoenolpyruvate carboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.31 4.1.1.31] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JQN OCA].  

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