title: 'Come into the fold': A comparative analysis of bacterial redox enzyme maturation protein members of the NarJ subfamily.
abstract: Redox enzyme maturation proteins (REMPs) are system-specific chaperones required for the maturation of complex iron sulfur molybdoenzymes that are important for anaerobic respiration in bacteria. Although they perform similar biological roles, REMPs are strikingly different in terms of sequence, structure, systems biology, and type of terminal electron acceptor that it supports for growth. Here we critically dissect current knowledge pertaining to REMPs of the nitrate reductase delta superfamily, specifically recognized in Escherichia coli to include NarJ, NarW, TorD, DmsD, and YcdY, also referred to as the NarJ REMP subfamily. We show that NarJ subfamily members share sequence homology and similar structural features as revealed by alignments performed on structurally characterized REMPs. We include an updated phylogenetic analysis of subfamily members, justifying their classification in this subfamily. The structural and functional roles of each member are presented herein and these discussions suggest that although NarJ subfamily members are related in sequence and structure, each member demonstrates remarkable uniqueness, validating the concept of system-specific chaperones.
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
authors.forename: Catherine S
authors.initials: CS
authors.lastname: Chan
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
authors.forename: Denice C
authors.initials: DC
authors.lastname: Bay
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
authors.forename: Thorin G H
authors.initials: TG
authors.lastname: Leach
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
authors.forename: Tara M L
authors.initials: TM
authors.lastname: Winstone
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
authors.forename: Lalita
authors.initials: L
authors.lastname: Kuzniatsova
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
authors.forename: Vy A
authors.initials: VA
authors.lastname: Tran
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada. Electronic address: turnerr@ucalgary.ca.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Turner
keywords: Complex iron–sulfur molybdoenzyme; Protein folding and enzyme maturation; Redox enzyme maturation protein; Respiratory enzyme biogenesis; Twin-arginine translocation