title: The catalytic efficiency of trehalose-6-phosphate synthase is effected by the N-loop at low temperatures.
abstract: The enzyme OtsA (trehalose-6-phosphate synthase) is ubiquitous in both prokaryotic and eukaryotic organisms, where it plays a critical role in stress resistance and glucose metabolism. Here, we cloned the otsA gene from Arthrobacter sp. Cjts, and expressed and then purified the recombinant proteins. Enzyme activity analysis indicated that the high catalytic efficiency of OtsA from Arthrobacter sp. Cjts resulted from the high affinity of the enzyme for uridine 5'-diphosphoglucose (UDP-Glc) at low temperatures. We also confirmed that the N-loop sequence of OtsA has a large effect on its affinity for UDP-Glc. Sequence analysis indicated that the flexibility of the N-loop may be directly related to the catalytic efficiency of OtsA at low temperatures.
authors.affiliation: Key Laboratory of Arid and Grassland Agroecology of the Ministry of Education, School of Life Sciences, Lanzhou University, 730000, Lanzhou, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jiang
authors.forename: Xi-Ming
authors.initials: XM
authors.lastname: Chen
authors.forename: Ya-Jie
authors.initials: YJ
authors.lastname: Liu
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Li
authors.forename: Hai-Hong
authors.initials: HH
authors.lastname: Zhang
authors.forename: Paul
authors.initials: P
authors.lastname: Dyson
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Sheng
authors.forename: Li-Zhe
authors.initials: LZ
authors.lastname: An
mesh_terms: D000595:Amino Acid Sequence; D001173:Arthrobacter / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D003080:Cold Temperature; D005798:Genes, Bacterial; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014532:Uridine Diphosphate Glucose / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase; D014532:Uridine Diphosphate Glucose