title: Involvement of the molybdenum cofactor biosynthetic machinery in the maturation of the Escherichia coli nitrate reductase A.
abstract: The maturation of Escherichia coli nitrate reductase A requires the incorporation of the Mo-(bis-MGD) cofactor to the apoprotein. For this process, the NarJ chaperone is strictly required. We report the first description of protein interactions between molybdenum cofactor biosynthetic proteins (MogA, MoeA, MobA, and MobB) and the aponitrate reductase (NarG) using a bacterial two-hybrid approach. Two conditions have to be satisfied to allow the visualization of the interactions, (i) the presence of an active and mature molybdenum cofactor and (ii) the presence of the NarJ chaperone and of the NarG structural partner subunit, NarH. Formation of tungsten-substituted cofactor prevents the interaction between NarG and the four biosynthetic proteins. Our results suggested that the final stages of molybdenum cofactor biosynthesis occur on a complex made up by MogA, MoeA, MobA, and MobB, which is also in charge with the delivery of the mature cofactor onto the aponitrate reductase A in a NarJ-assisted process.
authors.affiliation: Laboratoire de Chimie Bactérienne, Institut Biologie Structurale et Microbiologie, CNRS 31, chemin Joseph Aiguier cedex 09, 13402 Marseille, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Vergnes
authors.forename: Kamila
authors.initials: K
authors.lastname: Gouffi-Belhabich
authors.forename: Francis
authors.initials: F
authors.lastname: Blasco
authors.forename: Gérard
authors.initials: G
authors.lastname: Giordano
authors.forename: Axel
authors.initials: A
authors.lastname: Magalon
mesh_terms: D001059:Apoproteins / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000378:metabolism; D046911:Macromolecular Substances; D018832:Molecular Chaperones / Q000378:metabolism; D008982:Molybdenum; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000096:biosynthesis*; D021122:Protein Subunits / Q000378:metabolism; D013466:Sulfurtransferases / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D001059:Apoproteins; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; C490938:MobB protein, E coli; C099206:MobB protein, bacteria; C404104:Mog protein, E coli; D018832:Molecular Chaperones; D021122:Protein Subunits; D015534:Trans-Activators; C095754:mobA protein, E coli; D008982:Molybdenum; D009565:Nitrate Reductases; D050901:Nitrate Reductase; C111302:MoeA protein, E coli; D013466:Sulfurtransferases