HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 281, Issue 6, 3633-3641, February 10, 2006

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 281/6/3633    most recent M508696200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gengenbacher, M. Articles by Kappes, B. Search for Related Content PubMed PubMed Citation Articles by Gengenbacher, M. Articles by Kappes, B. Social Bookmarking                      What's this?

Vitamin B6 Biosynthesis by the Malaria Parasite Plasmodium falciparum

BIOCHEMICAL AND STRUCTURAL INSIGHTS^*

Martin Gengenbacher, Teresa B. Fitzpatrick, Thomas Raschle¹, Karlheinz Flicker^¶, Irmgard Sinning^||, Sylke Müller^**2, Peter Macheroux^¶3, Ivo Tews^||4, and Barbara Kappes⁵

From the Abteilung für Parasitologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, D-69120 Heidelberg, Germany, the eidgenössische Technische Hochschule Zürich, Institut für Pflanzenwissenschaften, Universitätsstrasse 2, CH-8092 Zürich, Switzerland, the ^¶Technische Universität Graz, Institut für Biochemie, Petersgasse 12, A-8010 Graz, Austria, the ^||Department of Structural Biology, Biochemiezentrum der Universität Heidelberg, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany, and the ^**Institute of Biomedical and Life Sciences, Division of Infection and Immunity, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom

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 Å. The obstruction of the oxyanion hole indicates that Pdx2 is in a resting state and that activation occurs upon Pdx1-Pdx2 complex formation.

Received for publication, August 8, 2005 , and in revised form, November 17, 2005.

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank^TM/EBI Data Bank with accession number(s) DQ077732 [GenBank] .

The atomic coordinates and structure factors (code 2ABW) have been deposited in the Protein Data Bank, Research Collaboratory for Structural Bioinformatics, Rutgers University, New Brunswick, NJ (http://www.rcsb.org/).

^* This work was supported in part by the European Commission (Grant VITBIOMAL-012158). Data collection was performed at beamline ID29 (ESRF, Grenoble). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. S1-S3.

¹ Supported by the Swiss National Science Foundation (Grant 3100A0-107975).

² A Wellcome Trust Senior Fellow.

³ Thanks the Austrian Fonds zur Förderung der wissenschaftlichen Forschung for generous financial support (Grant FWF 17215).

⁴ To whom correspondence may be addressed. Tel.: 49-6221-544788; Fax: 49-6221-544790; E-mail: ivo.tews{at}bzh.uni-heidelberg.de.

⁵ To whom correspondence may be addressed. Tel.: 49-6221-561774; Fax: 49-6221-564643; E-mail: barbara.kappes{at}urz.uni-heidelberg.de.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				J. P. Craig, S. Bekal, M. Hudson, L. Domier, T. Niblack, and K. N. Lambert Analysis of a Horizontally Transferred Pathway Involved in Vitamin B6 Biosynthesis from the Soybean Cyst Nematode Heterodera glycines Mol. Biol. Evol., October 1, 2008; 25(10): 2085 - 2098. [Abstract] [Full Text] [PDF]

				M. Tambasco-Studart, I. Tews, N. Amrhein, and T. B. Fitzpatrick Functional Analysis of PDX2 from Arabidopsis, a Glutaminase Involved in Vitamin B6 Biosynthesis Plant Physiology, June 1, 2007; 144(2): 915 - 925. [Abstract] [Full Text] [PDF]

				T. Raschle, D. Arigoni, R. Brunisholz, H. Rechsteiner, N. Amrhein, and T. B. Fitzpatrick Reaction Mechanism of Pyridoxal 5'-Phosphate Synthase: DETECTION OF AN ENZYME-BOUND CHROMOPHORIC INTERMEDIATE J. Biol. Chem., March 2, 2007; 282(9): 6098 - 6105. [Abstract] [Full Text] [PDF]

				M. Strohmeier, T. Raschle, J. Mazurkiewicz, K. Rippe, I. Sinning, T. B. Fitzpatrick, and I. Tews Structure of a bacterial pyridoxal 5'-phosphate synthase complex PNAS, December 19, 2006; 103(51): 19284 - 19289. [Abstract] [Full Text] [PDF]

				S. Wagner, A. Bernhardt, J. E. Leuendorf, C. Drewke, A. Lytovchenko, N. Mujahed, C. Gurgui, W. B. Frommer, E. Leistner, A. R. Fernie, et al. Analysis of the Arabidopsis rsr4-1/pdx1-3 Mutant Reveals the Critical Function of the PDX1 Protein Family in Metabolism, Development, and Vitamin B6 Biosynthesis PLANT CELL, July 1, 2006; 18(7): 1722 - 1735. [Abstract] [Full Text] [PDF]