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.