2ABW
Glutaminase subunit of the plasmodial PLP synthase (Vitamin B6 biosynthesis)
Summary for 2ABW
| Entry DOI | 10.2210/pdb2abw/pdb |
| Related | 1R9G |
| Descriptor | Pdx2 protein, TETRAETHYLENE GLYCOL (3 entities in total) |
| Functional Keywords | glutaminase, plp-synthase, vitamin b6, malaria, transferase |
| Biological source | Plasmodium falciparum (malaria parasite P. falciparum) |
| Total number of polymer chains | 2 |
| Total formula weight | 51514.89 |
| Authors | Gengenbacher, M.,Fitzpatrick, T.B.,Raschle, T.,Flicker, K.,Sinning, I.,Mueller, S.,Macheroux, P.,Tews, I.,Kappes, B. (deposition date: 2005-07-17, release date: 2006-01-10, Last modification date: 2023-10-25) |
| Primary citation | Gengenbacher, M.,Fitzpatrick, T.B.,Raschle, T.,Flicker, K.,Sinning, I.,Mueller, S.,Macheroux, P.,Tews, I.,Kappes, B. Vitamin B6 Biosynthesis by the Malaria Parasite Plasmodium falciparum: Biochemical and structural insights J.Biol.Chem., 281:3633-3641, 2006 Cited by PubMed Abstract: 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. PubMed: 16339145DOI: 10.1074/jbc.M508696200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.62 Å) |
Structure validation
Download full validation report
