2abw
From Proteopedia
(New page: 200px<br /><applet load="2abw" size="350" color="white" frame="true" align="right" spinBox="true" caption="2abw, resolution 1.620Å" /> '''Glutaminase subunit...) |
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==Overview== | ==Overview== | ||
| - | Vitamin B6 is one of nature's most versatile cofactors. Most organisms | + | Vitamin B6 is one of nature's most versatile cofactors. Most organisms synthesize vitamin B6 via a recently discovered pathway employing the proteins Pdx1 and Pdx2. Here we present an in-depth characterization of the respective orthologs from the malaria parasite, Plasmodium falciparum. Expression profiling of Pdx1 and -2 shows that blood-stage parasites indeed possess a functional vitamin B6 de novo biosynthesis. Recombinant Pdx1 and Pdx2 form a complex that functions as a glutamine amidotransferase with Pdx2 as the glutaminase and Pdx1 as pyridoxal-5 '-phosphate synthase domain. Complex formation is required for catalytic activity of either domain. Pdx1 forms a chimeric bi-enzyme with the bacterial YaaE, a Pdx2 ortholog, both in vivo and in vitro, although this chimera does not attain full catalytic activity, emphasizing that species-specific structural features govern the interaction between the protein partners of the PLP synthase complexes in different organisms. To gain insight into the activation mechanism of the parasite bi-enzyme complex, the three-dimensional structure of Pdx2 was determined at 1.62 A. The obstruction of the oxyanion hole indicates that Pdx2 is in a resting state and that activation occurs upon Pdx1-Pdx2 complex formation. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Plasmodium falciparum]] | [[Category: Plasmodium falciparum]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Fitzpatrick, T | + | [[Category: Fitzpatrick, T B.]] |
[[Category: Flicker, K.]] | [[Category: Flicker, K.]] | ||
[[Category: Gengenbacher, M.]] | [[Category: Gengenbacher, M.]] | ||
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[[Category: vitamin b6]] | [[Category: vitamin b6]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:25:53 2008'' |
Revision as of 14:25, 21 February 2008
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Glutaminase subunit of the plasmodial PLP synthase (Vitamin B6 biosynthesis)
Overview
Vitamin B6 is one of nature's most versatile cofactors. Most organisms synthesize vitamin B6 via a recently discovered pathway employing the proteins Pdx1 and Pdx2. Here we present an in-depth characterization of the respective orthologs from the malaria parasite, Plasmodium falciparum. Expression profiling of Pdx1 and -2 shows that blood-stage parasites indeed possess a functional vitamin B6 de novo biosynthesis. Recombinant Pdx1 and Pdx2 form a complex that functions as a glutamine amidotransferase with Pdx2 as the glutaminase and Pdx1 as pyridoxal-5 '-phosphate synthase domain. Complex formation is required for catalytic activity of either domain. Pdx1 forms a chimeric bi-enzyme with the bacterial YaaE, a Pdx2 ortholog, both in vivo and in vitro, although this chimera does not attain full catalytic activity, emphasizing that species-specific structural features govern the interaction between the protein partners of the PLP synthase complexes in different organisms. To gain insight into the activation mechanism of the parasite bi-enzyme complex, the three-dimensional structure of Pdx2 was determined at 1.62 A. The obstruction of the oxyanion hole indicates that Pdx2 is in a resting state and that activation occurs upon Pdx1-Pdx2 complex formation.
About this Structure
2ABW is a Single protein structure of sequence from Plasmodium falciparum with as ligand. Full crystallographic information is available from OCA.
Reference
Vitamin B6 biosynthesis by the malaria parasite Plasmodium falciparum: biochemical and structural insights., Gengenbacher M, Fitzpatrick TB, Raschle T, Flicker K, Sinning I, Muller S, Macheroux P, Tews I, Kappes B, J Biol Chem. 2006 Feb 10;281(6):3633-41. Epub 2005 Dec 8. PMID:16339145
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