A novel alkyl hydroperoxidase (AhpD) of Anabaena PCC7120 confers abiotic stress tolerance in Escherichia coli.
In silico analysis together with cloning, molecular characterization and heterologous expression reports that the hypothetical protein All5371 of Anabaena sp. PCC7120 is a novel hydroperoxide scavenging protein similar to AhpD of bacteria. The presence of E(X)11CX HC(X)3H motif in All5371 confers peroxidase activity and closeness to bacterial AhpD which is also reflected by its highest 3D structure homology with Rhodospirillum rubrum AhpD. Heterologous expression of all5371 complimented for ahpC and conferred resistance in MJF178 strain (ahpCF::Km) of Escherichia coli. All5371 reduced the organic peroxide more efficiently than inorganic peroxide and the recombinant E. coli strain following exposure to H2O2, CdCl2, CuCl2, heat, UV-B and carbofuron registered increased growth over wild-type and mutant E. coli transformed with empty vector. Appreciable expression of all5371 in Anabaena sp. PCC7120 as measured by qRT-PCR under selected stresses and their tolerance against H2O2, tBOOH, CuOOH and menadione attested its role in stress tolerance. In view of the above, All5371 of Anabaena PCC7120 emerged as a new hydroperoxide detoxifying protein.
Molecular Biology Section, Laboratory of Algal Biology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India.
Alok Kumar
AK
Shrivastava
Shilpi
S
Singh
Prashant Kumar
PK
Singh
Sarita
S
Pandey
L C
LC
Rai
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D017033:Anabaena / Q000201:enzymology*; D003001:Cloning, Molecular; D004789:Enzyme Activation; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D005816:Genetic Complementation Test; D006861:Hydrogen Peroxide; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000378:metabolism; D010544:Peroxidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D040681:Structural Homology, Protein; D013379:Substrate Specificity; D013696:Temperature; D014170:Transformation, Genetic
D009249:NADP; D006861:Hydrogen Peroxide; D010544:Peroxidases; D009195:Peroxidase