title: The copper supply pathway to a Salmonella Cu,Zn-superoxide dismutase (SodCII) involves P(1B)-type ATPase copper efflux and periplasmic CueP.
abstract: Periplasmic Cu,Zn-superoxide dismutases (Cu,Zn-SODs) are implicated in bacterial virulence. It has been proposed that some bacterial P(1B)-type ATPases supply copper to periplasmic cupro-proteins and such transporters have also been implicated in virulence. Here we show that either of two P(1B)-type ATPases, CopA or GolT, is needed to activate a periplasmic Cu,Zn-SOD (SodCII) in Salmonella enterica serovar Typhimurium. A ΔcopA/ΔgolT mutant accumulates inactive Zn-SodCII which can be activated by copper-supplementation in vitro. In contrast, either single ATPase mutant accumulates fully active Cu,Zn-SodCII. A contribution of GolT to copper handling is consistent with its copper-responsive transcription mediated by DNA-binding metal-responsive activator GolS. The requirement for duplicate transcriptional activators CueR and GolS remains unclear since both have similar tight K(Cu). Mutants lacking periplasmic cupro-protein CueP also accumulate inactive Zn-SodCII and while CopA and GolT show functional redundancy, both require CueP to activate SodCII in vivo. Zn-SodCII is also activated in vitro by incubation with Cu-CueP and this coincides with copper transfer as monitored by electron paramagnetic resonance spectroscopy. These experiments establish a role for CueP within the copper supply pathway for Salmonella Cu,Zn-SodCII. Copper binding by CueP in this pathogen may confer protection of the periplasm from copper-mediated damage while sustaining vital cupro-enzyme activity.
authors.affiliation: Life Sciences, Michael Smith Building, University of Manchester, Manchester M13 9PT, UK.
authors.forename: Deenah
authors.initials: D
authors.lastname: Osman
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Patterson
authors.forename: Kathryn
authors.initials: K
authors.lastname: Bailey
authors.forename: Karl
authors.initials: K
authors.lastname: Fisher
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Robinson
authors.forename: Stephen E J
authors.initials: SE
authors.lastname: Rigby
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Cavet
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D017353:Gene Deletion; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C071263:CopA protein, Bacteria; D026901:Membrane Transport Proteins; C023548:copper-binding protein; D003300:Copper; D013482:Superoxide Dismutase; D000251:Adenosine Triphosphatases