Manganese-containing superoxide dismutase and its gene from Candida albicans Gi-eun Rhie, Cheol-Sang Hwang, Martin J. Brady, Seong-Tae Kim, Yeon-Ran Kim, Won-Ki Huh, Yong-Un Baek, Byung-Hoon Lee, Jung-Sin Lee, Sa-Ouk Kang * Laboratory of Biophysics, Department of Microbiology, College of Natural Sciences, and Research Center for Molecular Microbiology, Seoul National University, Seoul 151-742, South Korea Received 26 August 1998; received in revised form 5 November 1998; accepted 10 November 1998 Abstract Mitochondrial manganese-containing superoxide dismutase was purified around 112-fold with an overall yield of 1.1% to apparent electrophoretic homogeneity from the dimorphic pathogenic fungus, Candida albicans. The molecular mass of the native enzyme was 106 kDa and the enzyme was composed of four identical subunits with a molecular mass of 26 kDa. The enzyme was not sensitive to either cyanide or hydrogen peroxide. The N-terminal amino acid sequence alignments (up to the 18th residue) showed that the enzyme has high similarity to the other eukaryotic manganese-containing superoxide dismutases. The gene sod2 encoding manganese-containing superoxide dismutase has been cloned using a product obtained from polymerase chain reaction. Sequence analysis of the sod2 predicted a manganese-containing superoxide dismutase that contains 234 amino acid residues with a molecular mass of 26 173 Da, and displayed 57% sequence identity to the homologue of Saccharomyces cerevisiae. The deduced N-terminal 34 amino acid residues may serve as a signal peptide for mitochondrial translocation. Several regulatory elements such as stress responsive element and haem activator protein 2/3/4/5 complex binding sites were identified in the promoter region of sod2. Northern analysis with a probe derived from the cloned sod2 revealed a 0.94-kb band, which corresponds approximately to the expected size of mRNA deduced from sod2. ß 1999 Elsevier Science B.V. All rights reserved. Keywords : Manganese-containing superoxide dismutase ; Sod2 ; Nucleotide sequence; Open reading frame; (Candida albicans) 1. Introduction Superoxide dismutase (SOD) is a metalloenzyme that catalyses the disproportionation of superoxide radical anion to hydrogen peroxide and oxygen mol- ecule [1]. This enzyme plays an important role in the protection of cells from oxidative damage of super- oxide radical anion [2]. Cell damage may also be due to the superoxide radical anion itself or, indirectly, to even more reactive oxygen species (ROS), such as hydroxyl radicals formed by the Fenton-driven Hab- er-Weiss reaction, in which superoxide radical anion combines with hydrogen peroxide [3]. Generally, SODs are categorised into four classes according to their metal contents: copper- and zinc-containing SOD (CuZnSOD) [1], manganese-containing SOD (MnSOD) [4], iron-containing SOD (FeSOD) [5], and nickel-containing SOD (NiSOD) [6,7]. MnSOD has been found in the mitochondrial matrix of eukar- yotes and in the cytosolic fractions of prokaryotes, 0304-4165 / 99 / $ ^ see front matter ß 1999 Elsevier Science B.V. All rights reserved. PII:S0304-4165(98)00161-5 * Corresponding author. Fax: +82 (2) 888-4911; E-mail : kangsaou@plaza.snu.ac.kr Biochimica et Biophysica Acta 1426 (1999) 409^419