title: Unusual pairing between assistants: interaction of the twin-arginine system-specific chaperone DmsD with the chaperonin GroEL.
abstract: DmsD is a system-specific chaperone that mediates the biogenesis and maturation of DMSO reductase in Escherichia coli. It is required for DmsAB holoenzyme formation and its targeting to the cytoplasmic membrane for translocation by the twin-arginine translocase. Previous studies suggested that DmsD also interacts with general molecular chaperones to assist in folding of the reductase subunits. Here, the interaction between DmsD and GroEL was further characterized to understand the role of GroEL in DMSO reductase maturation. The inherently weak interaction between the two was strengthened in vivo under growth conditions that induce DMSO reductase expression, and the DmsD-GroEL complex showed negligible change in hydrodynamic diameter by dynamic light scattering when cross-linked. Mapping the cross-linked sites on DmsD shows that the GroEL binding site is in close proximity to the previously characterized DmsA leader binding site. These findings support a role of GroEL in DMSO reductase maturation that likely involves its chaperonin function for assisting in folding of the DmsA preprotein.
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Catherine S
authors.initials: CS
authors.lastname: Chan
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Xiao
authors.initials: X
authors.lastname: Song
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: S Junaid S
authors.initials: SJ
authors.lastname: Qazi
authors.affiliation: Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Dheva
authors.initials: D
authors.lastname: Setiaputra
authors.affiliation: Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Calvin K
authors.initials: CK
authors.lastname: Yip
authors.affiliation: Institute of Environmental Change and Society, University of Regina, Regina, Saskatchewan, Canada.
authors.forename: Tzu-Chiao
authors.initials: TC
authors.lastname: Chao
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada. Electronic address: turnerr@ucalgary.ca.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Turner
mesh_terms: D001665:Binding Sites; D055592:Biophysical Phenomena; D002352:Carrier Proteins / Q000378:metabolism*; D018834:Chaperonin 60 / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D008027:Light; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D012542:Scattering, Radiation
chemical_list: D002352:Carrier Proteins; D018834:Chaperonin 60; C434268:DmsD protein, E coli; D029968:Escherichia coli Proteins; D047908:Intracellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins; C408585:twin-arginine translocase complex, E coli
keywords: DMSO reductase biogenesis; DmsD; GroEL; Protein-assisted folding; Redox enzyme maturation protein