title: Evidence for an additional disulfide reduction pathway in Escherichia coli.
abstract: An Escherichia coli cell-free protein synthesis cell extract has been created that lacks all known cytoplasmic disulfide reduction pathways but still retains significant reductase activity. Oxidized glutathione was partially stabilized by deleting the gene for glutathione reductase. To avoid previously reported AhpC mutations, thioredoxin reductase was only removed after extract preparation. The trxB gene was extended to encode a hemagglutinin tag so that TrxB could be removed by affinity adsorption. However, significant glutathione reductase activity remained. The unknown glutathione reductase pathway is disabled by iodoacetamide, is inhibited by NADH, and appears to use NADPH as an electron source.
authors.affiliation: Department of Chemical Engineering, Stanford University, 381 North-South Mall, Stanford, CA 94305, USA.
authors.forename: Kurtis G
authors.initials: KG
authors.lastname: Knapp
authors.forename: James R
authors.initials: JR
authors.lastname: Swartz
mesh_terms: D002474:Cell-Free System / Q000737:chemistry / Q000201:enzymology; D004220:Disulfides / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry* / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics; D017353:Gene Deletion; D005980:Glutathione Reductase / Q000737:chemistry / Q000172:deficiency; D009249:NADP / Q000737:chemistry; D010084:Oxidation-Reduction; D013880:Thioredoxin-Disulfide Reductase / Q000737:chemistry / Q000172:deficiency
chemical_list: D004220:Disulfides; D029968:Escherichia coli Proteins; D009249:NADP; D005980:Glutathione Reductase; D013880:Thioredoxin-Disulfide Reductase