title: Characterization of a bacterioferritin comigratory protein family 1-Cys peroxiredoxin from Candidatus Liberibacter asiaticus.
abstract: To defend against the lethality of the reactive oxygen species (ROS), nature has armed microorganisms with a range of antioxidant proteins. These include peroxiredoxin (Prx) super family proteins which are ubiquitous cysteine-based non-heme peroxidases. The phytopathogenic bacterium Candidatus Liberibacter asiaticus (CLA), an etiological agent of citrus plants diseases, posses many genes for defense against oxidative stress. The bacterioferritin comigratory protein (BCP), a member of Prxs, is part of an oxidative stress defense system of CLA. The key residue of these enzymes is peroxidatic Cys (termed CPSH) which is contained within an absolutely conserved PXXX (T/S) XXC motif. In the present study, a 1-Cys Prx enzyme (CLa-BCP), having CPSH/sulfenic acid cysteine (C-46) but lacking the resolving cysteine (CRSH), was characterized from CLA. The peroxidase activity was demonstrated using a non-physiological electron donor DTT against varied substrates. The protein was shown to have the defensive role against peroxide-mediated cell killing and an antioxidant activity. In vitro DNA-binding studies showed that this protein can protect supercoiled DNA from oxidative damage. To the best of our knowledge, this is the first report on a 1-Cys BCPs to have an intracellular reactive oxygen species scavenging activity.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247 667, India.
authors.forename: Anamika
authors.initials: A
authors.lastname: Singh
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247 667, India.
authors.forename: Narender
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247 667, India.
authors.forename: Prabhat P S
authors.initials: PPS
authors.lastname: Tomar
authors.affiliation: Plant Virology Laboratory, ICAR-Central Citrus Research Institute, Nagpur, 440 010, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Bhose
authors.affiliation: Plant Virology Laboratory, ICAR-Central Citrus Research Institute, Nagpur, 440 010, India.
authors.forename: Dilip Kumar
authors.initials: DK
authors.lastname: Ghosh
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247 667, India.
authors.forename: Partha
authors.initials: P
authors.lastname: Roy
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247 667, India. aksbsfbs@yahoo.co.in.
authors.forename: Ashwani K
authors.initials: AK
authors.lastname: Sharma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D019556:COS Cells; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D003573:Cytochrome b Group / Q000737:chemistry; D005293:Ferritins / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000494:pharmacology; D061986:MCF-7 Cells; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D054464:Peroxiredoxins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D012230:Rhizobiaceae / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D003573:Cytochrome b Group; D016166:Free Radical Scavengers; D005293:Ferritins; C018032:bacterioferritin; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins
keywords: 1-Cys peroxiredoxin; Bacterioferritin comigratory protein (BCP); Candidatus Liberibacter asiaticus (CLA); DNA binding; Peroxidase activity