![]()
|
|
||||||||
J. Biol. Chem., Vol. 282, Issue 25, 18254-18264, June 22, 2007
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||







1
From the
Biology Department and Program in Molecular Plant Biology, Colorado State University, Fort Collins, Colorado 80523, the
Laboratoire de Chimie et Biologie des Métaux, UMR UJF/CEA/CNRS no. 5249, Institut de Recherche en Technologie et Sciences pour le Vivant/Laboratoire de Chimie et Biologie des Métauk, CEA Grenoble, 17 Avenue des Martyrs, 38054 Grenoble, Cedex 09, France, and the ¶NCSR, Demokritos, Institute of Materials Science, 15310 Ag. Paraskevi, Attiki, Greece
In this study we characterize two novel chloroplast SufE-like proteins from Arabidopsis thaliana. Other SufE-like proteins, including the previously described A. thaliana CpSufE, participate in sulfur mobilization for Fe-S biosynthesis through activation of cysteine desulfurization by NifS-like proteins. In addition to CpSufE, the Arabidopsis genome encodes two other proteins with SufE domains, SufE2 and SufE3. SufE2 has plastid targeting information. Purified recombinant SufE2 could activate the cysteine desulfurase activity of CpNifS 40-fold. SufE2 expression was flower-specific and high in pollen; we therefore hypothesize that SufE2 has a specific function in pollen Fe-S cluster biosynthesis. SufE3, also a plastid targeted protein, was expressed at low levels in all major plant organs. The mature SufE3 contains two domains, one SufE-like and one with similarity to the bacterial quinolinate synthase, NadA. Indeed SufE3 displayed both SufE activity (stimulating CpNifS cysteine desulfurase activity 70-fold) and quinolinate synthase activity. The full-length protein was shown to carry a highly oxygen-sensitive (4Fe-4S) cluster at its NadA domain, which could be reconstituted by its own SufE domain in the presence of CpNifS, cysteine and ferrous iron. Knock-out of SufE3 in Arabidopsis is embryolethal. We conclude that SufE3 is the NadA enzyme of A. thaliana, involved in a critical step during NAD biosynthesis.
Received for publication, February 16, 2007 , and in revised form, April 11, 2007.
* This work was supported by United States Department of Agriculture Grant USDA-NRI 2005-35318-16212 (to E. P. S. and M. P.). 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 Fig. 1.
This article was selected as a Paper of the Week.
1 To whom correspondence should be addressed. Tel.: 970-491-0803; Fax: 970-491-0649; E-mail: pilon{at}lamar.colostate.edu.
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
J. Godman and J. Balk Genome Analysis of Chlamydomonas reinhardtii Reveals The Existence of Multiple, Compartmentalized Iron-Sulfur Protein Assembly Machineries of Different Evolutionary Origins Genetics, May 1, 2008; 179(1): 59 - 68. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |