Crystal structure and biochemical characterization of a manganese superoxide dismutase from Chaetomium thermophilum

• Published in: Biochimica et biophysica acta Vol. 1844; no. 2; pp. 422 - 429
• Main Authors: Haikarainen, Teemu, Frioux, Clémence, Zhnag, Li-Qing, Li, Duo-Chuan, Papageorgiou, Anastassios C.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2014
• Subjects: Amino Acid Sequence; Antioxidant; Aspergillus fumigatus; Biochemistry, Molecular Biology; Bioinformatics; Catalytic Domain; Chaetomium; Chaetomium - enzymology; Computer Science; Crystallography, X-Ray; Dismutation; Endoplasmic Reticulum Stress - physiology; Enzyme Stability; Fungal enzyme; Life Sciences; Metal binding; Models, Molecular; Molecular Sequence Data; Oxidative stress; Pichia; Pichia pastoris; Protein Conformation; Sequence Homology, Amino Acid; Structural Biology; Superoxide Dismutase - chemistry; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; Thermostability; Thermostability; Oxidative stress; SAA; Dismutation; CtMnSOD; RSAA; Fungal enzyme; Metal binding; Antioxidant; relative solvent accessible area; solvent accessible area; Chaetomium thermophilum manganese superoxide dismutase
• ISSN: 1570-9639; 0006-3002; 1878-1454; 1878-2434
• DOI: 10.1016/j.bbapap.2013.11.014

A manganese superoxide dismutase from the thermophilic fungus Chaetomium thermophilum (CtMnSOD) was expressed in Pichia pastoris and purified to homogeneity. Its optimal temperature was 60°C with approximately 75% of its activity retained after incubation at 70°C for 60min. Recombinant yeast cells carrying C. thermophilum mnsod gene exhibited higher stress resistance to salt and oxidative stress-inducing agents than control yeast cells. In an effort to provide structural insights, CtMnSOD was crystallized and its structure was determined at 2.0Å resolution. The overall architecture of CtMnSOD was found similar to other MnSODs with highest structural similarities obtained against a MnSOD from the thermotolerant fungus Aspergillus fumigatus. In order to explain its thermostability, structural and sequence analysis of CtMnSOD with other MnSODs was carried out. An increased number of charged residues and an increase in the number of intersubunit salt bridges and the Thr:Ser ratio were identified as potential reasons for the thermostability of CtMnSOD. •CtMnSOD was produced in Pichia pastoris.•Crystal structure was determined at 2.0Å resolution.•Reasons for the thermostability of CtMnSOD are suggested.•Structural similarities with MnSOD from Aspergillus fumigatus were found.•ctmnsod gene was found to provide stress protection in yeast cells.