Na-Ranong Sutthicha, Laoteng Kobkul, Kittakoop Prasat, Tanticharoen Morakot, Cheevadhanarak Supapon
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkuntien, Bangkok 10150, Thailand.
Biochem Biophys Res Commun. 2006 Jan 27;339(4):1029-34. doi: 10.1016/j.bbrc.2005.11.115. Epub 2005 Dec 1.
The amino acid residues serine at position 213 (S213) and lysine at position 218 (K218), which are present in close proximity to the histidine-rich motif II of Mucor rouxii fatty acid Delta(6)-desaturase isoform II, were targeted for studying structure-function relationships using site-directed mutagenesis. The mutants were functionally characterized in a heterologous host, Saccharomyces cerevisiae. Substrate specificity and preference studies revealed that S213 and K218 are involved in substrate recognition. K218 plays a role in substrate preference by involvement in the binding of substrates, particularly C15-C18 monoene fatty acids. Modification of the M. rouxii Delta(6)-desaturase therefore has potential in specifically altering substrate utilization for production of desired fatty acids.
在鲁氏毛霉脂肪酸Δ(6)-去饱和酶同工型II富含组氨酸的基序II附近存在的213位丝氨酸（S213）和218位赖氨酸（K218）氨基酸残基，通过定点诱变被用于研究结构-功能关系。这些突变体在异源宿主酿酒酵母中进行了功能表征。底物特异性和偏好性研究表明，S213和K218参与底物识别。K218通过参与底物尤其是C15 - C18单烯脂肪酸的结合，在底物偏好中发挥作用。因此，鲁氏毛霉Δ(6)-去饱和酶的修饰在特异性改变底物利用以生产所需脂肪酸方面具有潜力。
