JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Abola, A. P.
Right arrow Articles by Long, S. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Abola, A. P.
Right arrow Articles by Long, S. R.

 Previous Article  |  Next Article 

Journal of Bacteriology, September 1999, p. 5280-5287, Vol. 181, No. 17
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Reduction of Adenosine-5'-Phosphosulfate Instead of 3'-Phosphoadenosine-5'-Phosphosulfate in Cysteine Biosynthesis by Rhizobium meliloti and Other Members of the Family Rhizobiaceae

A. Pia Abola, Michael G. Willits,dagger Richard C. Wang,Dagger and Sharon R. Long*

Howard Hughes Medical Institute, Department of Biological Sciences, Stanford University, Stanford, California 94305-5020

Received 27 January 1999/Accepted 23 June 1999

We have cloned and sequenced three genes from Rhizobium meliloti (Sinorhizobium meliloti) that are involved in sulfate activation for cysteine biosynthesis. Two of the genes display homology to the Escherichia coli cysDN genes, which code for an ATP sulfurylase (EC 2.7.7.4). The third gene has homology to the E. coli cysH gene, a 3'-phosphoadenosine-5'-phosphosulfate (PAPS) reductase (EC 1.8.99.4), but has greater homology to a set of genes found in Arabidopsis thaliana that encode an adenosine-5'-phosphosulfate (APS) reductase. In order to determine the specificity of the R. meliloti reductase, the R. meliloti cysH homolog was histidine tagged and purified, and its specificity was assayed in vitro. Like the A. thaliana reductases, the histidine-tagged R. meliloti cysH gene product appears to favor APS over PAPS as a substrate, with a Km for APS of 3 to 4 µM but a Km for PAPS of >100 µM. In order to determine whether this preference for APS is unique to R. meliloti among members of the family Rhizobiaceae or is more widespread, cell extracts from R. leguminosarum, Rhizobium sp. strain NGR234, Rhizobium fredii (Sinorhizobium fredii), and Agrobacterium tumefaciens were assayed for APS or PAPS reductase activity. Cell extracts from all four species also preferentially reduce APS over PAPS.

* Corresponding author. Mailing address: Howard Hughes Medical Institute, Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020. Phone: (650) 723-3232. Fax: (650) 725-8309. E-mail: srl{at}leland.stanford.edu.

dagger Present address: Novartis Agribusiness Biotechnology Research, Inc., Research Triangle Park, NC 27709-2257.

Dagger Present address: Cellular and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.

Journal of Bacteriology, September 1999, p. 5280-5287, Vol. 181, No. 17
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1999 by the American Society for Microbiology. All rights reserved.