Substrate specificity and preference of Δ6‐desaturase of Mucor rouxii

The Δ6‐fatty acid desaturase is a key enzyme in the synthesis of an important fatty acid, γ‐linolenic acid. We have characterized, by heterologous expression in Saccharomyces cerevisiae, substrate specificity and preference of Δ6‐desaturase of Mucor rouxii. Fatty acid supplementation was carried out based on the predicted enzyme topology, fatty acid phenotype and the corresponding metabolic pathway in M. rouxii. The enzyme has a broad substrate specificity as based on C15–C18. The result also supported classification of the M. rouxii Δ6‐desaturase into a front‐end desaturase. Interestingly, a relatively rare activity based on odd acyl chains and not described previously in other eukaryotic Δ6‐desaturases was also observed.