title: Identification of substrate-binding and selectivity-related residues of maltooligosyltrehalose synthase from the thermophilic archaeon Sulfolobus solfataricus ATCC 35092.
abstract: Maltooligosyltrehalose synthase (MTSase) is a key enzyme in the synthesis of trehalose. Computer simulations using AutoDock and NAMD were employed to assess the substrate-binding and selectivity-related residues of MTSase. We introduced mutations at residues D411, D610, and R614 to determine the substrate-binding residues of Sulfolobus solfataricus ATCC 35092 MTSase, and introduced mutations at residues P402, A406, and V426 to investigate the enzyme's selectivity-related residues. Kinetic studies of D411A, D610A, and R614A MTSases reveal significant reductions in catalytic efficiency and cause increase in the transition-state energy of mutant MTSases, indicating that residues D411, D610, and R614 form hydrogen bonds to the substrate. Compared with wild-type MTSase, the hydrolysis: transglycosylation selectivity ratio was significantly decreased for P402Q and significantly increased for A406S MTSases, while the ratio for V426T MTSase showed little change. The results suggest that P402 and A406 residues are selectivity-related.
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan. Electronic address: tsengwc@mail.ntust.edu.tw.
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Tseng
authors.affiliation: Department of Food Science, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Chia-Ray
authors.initials: CR
authors.lastname: Lin
authors.affiliation: Department of Food Science, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Xing-Guang
authors.initials: XG
authors.lastname: Hung
authors.affiliation: Department of Food Science, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Tsen-Yun
authors.initials: TY
authors.lastname: Wei
authors.affiliation: Department of Food Science, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Food Science, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan. Electronic address: tyfang@mail.ntou.edu.tw.
authors.forename: Tsuei-Yun
authors.initials: TY
authors.lastname: Fang
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002384:Catalysis; D020134:Catalytic Domain; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006031:Glycosylation; D006860:Hydrogen Bonding; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013379:Substrate Specificity; D048229:Sulfolobus solfataricus / Q000201:enzymology* / Q000235:genetics
chemical_list: D019843:Archaeal Proteins; D005964:Glucosyltransferases; C099084:maltooligosyl trehalose synthase
keywords: Computer simulation; Hydrogen bond; Maltooligosyltrehalose synthase; Selectivity; Site-directed mutagenesis; Sulfolobus