The thioredoxin homolog YbbN functions as a chaperone rather than as an oxidoreductase

Biochemical and Biophysical Research Communications
Fatoum KthiriGilbert Richarme


Escherichia coli contains two thioredoxins, Trx1 and Trx2, and a thioredoxin-like protein, YbbN, which presents a strong homology in its N-terminal part with thioredoxins, and possesses a 20kDa C-terminal part of unknown function. We reported previously that YbbN displays both protein oxido-reductase and chaperone properties in vitro. In this study, we show that an ybbN-deficient strain displays an increased sensitivity to thermal stress but not to oxidative stress, a normal redox state of its cellular proteins but a decreased expression of several cytoplasmic proteins, including EF-Tu, DnaK, GroEL, trigger factor and several Krebs cycle enzymes, suggesting that the chaperone properties of YbbN are more important in vivo than its redox properties. YbbN specifically interacts with DnaK and GroEL, as shown by reverse purification. It increases 4-fold the rate of protein renaturation in vitro by the DnaK chaperone machine, suggesting that it cooperates with DnaK for the optimal expression of several cytoplasmic proteins.


Jul 20, 2011·The Journal of Biological Chemistry·Robert G SmockLila M Gierasch
Sep 29, 2011·Journal of Experimental Botany·Ruth Sanz-BarrioInmaculada Farran
Feb 16, 2011·Proteins·Carien DekkerWilliam R Taylor
Mar 11, 2020·Infection and Immunity·Sadia SultanaJan-Ulrik Dahl


Sep 11, 1999·Nucleic Acids Research·C S RichmondF R Blattner
Sep 30, 2000·European Journal of Biochemistry·E S Arnér, Arne Holmgren
Oct 19, 2001·Research in Microbiology·A de Crouy-Chanel, Gilbert Richarme
Jan 29, 2003·The Biochemical Journal·Renée KernGilbert Richarme
Mar 9, 2004·Proceedings of the National Academy of Sciences of the United States of America·Jaya K KumarCharles C Richardson
Nov 18, 2004·Journal of Bacteriology·Madhab K ChattopadhyayGilbert Richarme
Mar 10, 2005·Microbiology and Molecular Biology Reviews : MMBR·Alan J Wolfe
Oct 16, 2007·Journal of Bacteriology·Jad AbdallahGilbert Richarme

Related Concepts

TXNL1 gene
Covalent Interaction
Thioredoxin Reductase (NADPH)
Tissue Membrane
Hydrogen Peroxide
HSPD1 gene
DnaK protein, E coli
Heat-Shock Proteins 70
DNAJB6 wt Allele

Related Feeds

Biosynthetic Transformations

Biosyntheic transformtions are multi-step, enzyme-catalyzed processes where substrates are converted into more complex products in living organisms. Simple compounds are modified, converted into other compounds, or joined together to form macromolecules. Discover the latest research on biosynthetic transformations here.