An additional cysteine in a typical 2‐Cys peroxiredoxin ofPseudomonas promotes functional switching between peroxidase and molecular chaperone

摘要

Peroxiredoxins(Prx)havereceivedconsiderableattentionduringrecentyears.ThisstudydemonstratesthattwotypicalPseudomonas‐derived2‐CysPrxproteins,PpPrxandPaPrxcanalternativelyfunctionasaperoxidaseandchaperone.TheaminoacidsequencesofthesetwoPrxproteinsexhibit93%homology,butPpPrxpossessesanadditionalcysteineresidue,Cys112,insteadofthealaninefoundinPaPrx.PpPrxpredominateswithahighmolecularweight(HMW)complexandchaperoneactivity,whereasPaPrxhasmainlylowmolecularweight(LMW)structuresandperoxidaseactivity.MassspectrometryandstructuralanalysesshowedtheinvolvementofCys112intheformationofaninter‐disulfidebond,theinstabilityofLMWstructures,theformationofHMWcomplexes,andincreasedhydrophobicityleadingtofunctionalswitchingofPrxproteinsbetweenperoxidaseandchaperone...