2jd2: Difference between revisions

Isopentenyl diphosphate is the precursor of various isoprenoids that are, essential to all living organisms. It is produced by the mevalonate, pathway in humans but by an alternate route in plants, protozoa, and many, bacteria. 1-deoxy-D-xylulose-5-phosphate reductoisomerase catalyzes the, second step of this non-mevalonate pathway, which involves an, NADPH-dependent rearrangement and reduction of 1-deoxy-D-xylulose, 5-phosphate to form 2-C-methyl-D-erythritol 4-phosphate. The use of, different pathways, combined with the reported essentiality of the enzyme, makes the reductoisomerase a highly promising target for drug design. Here, we present several high resolution structures of the Mycobacterium, tuberculosis 1-deoxy-D-xylulose-5-phosphate reductoisomerase, representing, both wild type and mutant enzyme in various complexes with Mn(2+), NADPH, and the known inhibitor fosmidomycin. The asymmetric unit corresponds to, the biological homodimer. Although crystal contacts stabilize an open, active site in the B molecule, the A molecule displays a closed, conformation, with some differences depending on the ligands bound. An, inhibition study with fosmidomycin resulted in an estimated IC(50) value, of 80 nm. The double mutant enzyme (D151N/E222Q) has lost its ability to, bind the metal and, thereby, also its activity. Our structural information, complemented with molecular dynamics simulations and free energy, calculations provides the framework for the design of new inhibitors and, gives new insights into the reaction mechanism. The conformation of, fosmidomycin bound to the metal ion is different from that reported in a, previously published structure and indicates that a rearrangement of the, intermediate is not required during catalysis.

2JD2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis] with MN and SO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/1-deoxy-D-xylulose-5-phosphate_reductoisomerase 1-deoxy-D-xylulose-5-phosphate reductoisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.267 1.1.1.267] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2JD2 OCA].  

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