JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
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 Tsang, M L
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tsang, M L

 Previous Article  |  Next Article 

J Bacteriol. 1981 June; 146(3): 1059-1066

Assimilatory sulfate reduction in Escherichia coli: identification of the alternate cofactor for adenosine 3'-phosphate 5'-phosphosulfate reductase as glutaredoxin.

M L Tsang

ABSTRACT

The alternate cofactor (7004 cofactor) for Escherichia coli adenosine 3'-phosphate 5'-phosphosulfate (PAPS) reductase originally discovered in an E. coli mutant (tsnC 7004) lacking thioredoxin activity has now been purified and characterized. The tryptic peptide map of the 7004 cofactor is totally different from that of thioredoxin, indicating that the two proteins are unrelated in their primary structure. The 7004 cofactor has an amino acid composition different from that of thioredoxin but similar to that of glutaredoxin, a protein required for the glutathione-dependent deoxyribonucleotide formation by ribonucleotide reductase. Thus, the 7004 cofactor could not be a mutated form of thioredoxin, as was suspected earlier. Thioredoxin but not glutaredoxin is a substrate for thioredoxin reductase, but both thioredoxin and glutaredoxin can catalyze the dithiothreitol- or glutathione-dependent reduction of PAPS. On a molar basis, the dithiothreitol-coupled cofactor activity of thioredoxin is three- to fourfold higher that that of glutaredoxin. Comparison of the cofactor activities in the glutathione-coupled and the dithiothreitol-coupled PAPS reductase reaction shows that the cofactor activity of thioredoxin in the glutathione-coupled reaction is only 23% of that observed in the dithiothreitol-coupled reaction. However, in the case of glutaredoxin, cofactor activities are approximately the same in both the dithiothreitol- and glutathione-coupled reactions.


J Bacteriol. 1981 June; 146(3): 1059-1066




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 © 1981 by the American Society for Microbiology. All rights reserved.