Characterisation of conformational and functional features of alkyl hydroperoxide reductase E-like protein

• Published in: Biochemical and biophysical research communications Vol. 489; no. 2; pp. 217 - 222
• Main Authors: Lee, Sangmin, Jeong, Hyeongseop, Lee, Ju Huck, Chung, Jeong Min, Kim, Rumi, Yun, Hyung Joong, Won, Jonghan, Jung, Hyun Suk
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 22.07.2017
• Subjects: AhpE; Amino Acid Sequence; DNA binding protein; Holdase; Models, Molecular; Peroxidase; Peroxiredoxins - chemistry; Peroxiredoxins - metabolism; Protein Conformation; Sequence Alignment; Structure-function relationship; Thermococcus - metabolism; Thermococcus kodakarensis; RT; AhpE; DTT; Grx; Structure-function relationship; Thermococcus kodakarensis; EMSA; Prx; Peroxidase; Trx; EtBr; ssDNA; DNA binding protein; EM; SOD; EDTA; CP; CR; SEC; LB; DRE; ROS; SOR; Cat; MCO; dsDNA; Holdase
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2017.05.135

Alkyl hydroperoxide reductase E (AhpE) is a member of the peroxidase family of enzymes that catalyse the reduction of peroxides, however its structural and functional roles are still unclear in details. In this study, we used the Thermococcus kodakarensis AhpE-like protein as a model to investigate structure–function relationships including the molecular properties of DNA binding activity. Multiple sequence alignment, structural comparison and biochemical analyses revealed that TkAhpE includes conserved peroxidase residues in the active site, and exhibits peroxidase activity with structure-dependent holdase chaperone function. Following electrophoretic mobility shift assays and electron microscopy analysis demonstrated distinctive binding features of TkAhpE to the DNA showing that their dimeric conformer can bind to the double-stranded DNA, but not to the single-stranded DNA, indicating its striking molecular features to double-stranded DNA-specific interactions. Based on our results, we provided that TkAhpE is a multifunctional peroxidase displaying structure-dependent molecular chaperone and DNA binding activities. •Alkyl hydroperoxide reductase E acts as a multi-functional protein displaying peroxidase, holdase and DNA binding activities.•Thermococcus kodakarensis AhpE(TkAhpE) exhibits peroxidase activities with structure-dependent holdase chaperone function.•Recombinant TkAhpE is expressed as two different oligomeric forms, the dimeric and octameric conformers.•Unlikely an octameric conformer, dimeric state of TkAhpE can bind both double stranded circular and linear DNA molecules.