title: Evolution-related amino acids play important role in determining regioselectivity of fatty acid desaturase from Pichia pastoris.
abstract: Omega(3)-fatty acid desaturase and Delta(12)-fatty acid desaturase of Pichia pastoris with distinguishable regioselectivity and high degree of sequence similarity were chosen for regioselectivity research. Chimeras were constructed in which Histidine-rich boxes 1, 2 and the carboxyl terminal region of omega(3)-fatty acid desaturase were replaced with corresponding region of Delta(12)-fatty acid desaturase. The replacement was found to result in a change of regioselectivity from omegay to x + 3 by functionally characterizing these chimeric enzymes in Saccharomyces cerevisae strain INVScI. Using site-directed mutagenesis, we further demonstrated that seven conserved amino acids of omega(3)-fatty acid desaturase within the first two Histidine-rich regions are responsible for the regioselectivity switch. Therefore, the regioselectivity of fatty acid desaturases may be better understood by investigating the evolutionary relationships of different fatty acid desaturases.
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, Tianjin, PR China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhang
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Wei
authors.forename: Mingchun
authors.initials: M
authors.lastname: Li
authors.forename: Yuyan
authors.initials: Y
authors.lastname: Qi
authors.forename: Laijun
authors.initials: L
authors.lastname: Xing
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002849:Chromatography, Gas; D019143:Evolution, Molecular; D044943:Fatty Acid Desaturases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny; D010843:Pichia / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D011994:Recombinant Proteins; D044943:Fatty Acid Desaturases