Identification and Sequencing of Candida krusei Aconitate Hydratase Gene Using Rapid Amplification of cDNA Ends Method and Phylogenetic Analysis

BACKGROUND The production and development of an effective fungicidal drug requires the identification of an essential fungal protein as a drug target. Aconitase (ACO) is a mitochondrial protein that plays a vital role in tricarboxylic acid (TCA) cycle and thus production of energy within the cell. OBJECTIVES The current study aimed to sequence Candida krusei ACO gene and determine any amino acid residue differences between human and fungal aconitases to obtain selective inhibition. MATERIALS AND METHODS Candida krusei (ATCC: 6258) aconitase gene was determined by 5'Rapid Amplification of cDNA Ends (RACE) method and degenerate Polymerase Chain Reaction (PCR) and analyzed using bioinformatics softwares. RESULTS One thousand-four hundred-nineteen nucleotide of C. krusei aconitase gene were clarified and submitted in Genbank as a partial sequence and then taxonomic location of C. krusei was determined by nucleotide and amino acid sequences of this gene. The comparison of nucleotide and amino acid sequences of Candida species ACO genes showed that C. krusei possessed characteristic sequences. No significant differences were observed between C. krusei and human aconitases within the active site amino acid residues. CONCLUSIONS Results of the current study indicated that aconitase was not a suitable target to design new anti-fungal drugs that selectively block this enzyme.