Coenzyme Q is a quinone derivative that acts as a lipid electron carrier in the respiratory chain located at mito-chondrial inner membrane in eucaryotes or plasma membrane in procaryotes and also functions as antioxidant. A putative Neurospora crassa coq-4 gene was cloned and functionally expressed in Saccharomyces cerevisiae coq4 mutant. Complemented S. cerevisaie mutant strain was able to produce coenzyme $Q_{6}$ and showed a normal growth rate. They also showed less sensitivities to polyunsaturated fatty acids such as linoleic acid or linolenic acid. The predicted sequence of N. crassa COQ4 is consisted of 347 amino acids with a molecular mass of 39.7 kDa and showed 35% identity and 52% similarity with that of S. cerevisiae.