The metallo-beta-lactamase gene, ccrA, from Bacteroides fragilis is functionally expressed in Escherichia coli only in the presence of a genomic mutation in iarA or iarB (increased ampicillin resistance), identified in this study as dsbA or dsbB, respectively. DsbA and DsbB are components of a periplasmic protein disulfide bond-catalyzing system. Data indicated that DsbA interacted with CcrA, creating aberrant disulfide bond linkages that render CcrA proteolytically unstable. Mutations in dsbA or dsbB permissive for CcrA expression eliminated or greatly reduced DsbA activity, allowing CcrA to assume a disulfide bond-free and proteolytically stable conformation.
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http://dx.doi.org/10.1128/jb.177.2.462-464.1995 | DOI Listing |
J Biol Chem
June 2024
Department of Biology, Indiana University, Bloomington, Indiana, USA. Electronic address:
Disulfide bond formation has a central role in protein folding of both eukaryotes and prokaryotes. In bacteria, disulfide bonds are catalyzed by DsbA and DsbB/VKOR enzymes. First, DsbA, a periplasmic disulfide oxidoreductase, introduces disulfide bonds into substrate proteins.
View Article and Find Full Text PDFJ Bacteriol
April 2024
Department of Biology, Indiana University, Bloomington, Indiana, USA.
Unlabelled: In bacteria, disulfide bonds contribute to the folding and stability of proteins important for processes in the cellular envelope. In , disulfide bond formation is catalyzed by DsbA and DsbB enzymes. DsbA is a periplasmic protein that catalyzes disulfide bond formation in substrate proteins, while DsbB is an inner membrane protein that transfers electrons from DsbA to quinones, thereby regenerating the DsbA active state.
View Article and Find Full Text PDFACS Synth Biol
February 2022
Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. Coli, Department of Biotechnology, Institute of Bioprocess Science and Engineering, University of Natural Resources and Life Sciences, Vienna, Muthgasse 18, 1190 Vienna, Austria.
Antibody fragments such as Fab's require the formation of disulfide bonds to achieve a proper folding state. During their recombinant, periplasmic expression in , oxidative folding is mediated by the DsbA/DsbB system in concert with ubiquinone. Thereby, overexpression of Fab's is linked to the respiratory chain, which is not only immensely important for the cell's energy household but also known as a major source of reactive oxygen species.
View Article and Find Full Text PDFComput Struct Biotechnol J
August 2021
Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia.
The disulfide bond (DSB) forming system and in particular DsbA, is a key bacterial oxidative folding catalyst. Due to its role in promoting the correct assembly of a wide range of virulence factors required at different stages of the infection process, DsbA is a master virulence rheostat, making it an attractive target for the development of new virulence blockers. Although DSB systems have been extensively studied across different bacterial species, to date, little is known about how DsbA oxidoreductases are able to recognize and interact with such a wide range of substrates.
View Article and Find Full Text PDFCurr Genet
August 2021
Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India.
Long-chain fatty acids (LCFAs) are a tremendous source of metabolic energy, an essential component of membranes, and important effector molecules that regulate a myriad of cellular processes. As an energy-rich nutrient source, the role of LCFAs in promoting bacterial survival and infectivity is well appreciated. LCFA degradation generates a large number of reduced cofactors that may confer redox stress; therefore, it is imperative to understand how bacteria deal with this paradoxical situation.
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