Molecular cloning of a cDNA encoding enolase from the filamentous fungus, Aspergillus oryzae

A 1.6-kbp full-length cDNA for the Aspergillus oryzae enolase gene (enoA) was cloned. The sequenced insert contained a continuous open reading frame of 1314 bp encoding a protein of molecular weight 47 405. Among all enolases sequenced to-date, the deduced amino-acid sequence showed the highest homology (74.9%) with Candida albicans enolase (ENO1). Strong codon biases and multiple transcription start sites downstream from CT-blocks in the 5'-flanking region suggested strong expression. enoA mRNA was found to occupy approximately 3% (w/w) of total mRNA of A. oryzae by quantitative RT-PCR. This strong transcription was dependent on the carbon source in the medium and correlated with the growth rate of the mycelium.