Structural comparison of the substrate-binding mechanism between maltooligosyl trehalose synthase (MTSase) and maltooligosyl trehalose trehalohydrolase (MTHase)

Adachi, Motoyasu; Okazaki, Nobuo*; Tamada, Taro; Kato, Masaru*; Kobayashi, Kazuo*; Blaber, M.; Kuroki, Ryota

Maltooligosyl trehalose synthase (MTSase) and maltooligosyl trehalose trehalohydrolase (MTHase) are key enzymes for effective production of trehalose which is a useful compound as a preservative for foods. To understand the catalytic mechanism of MTSase, the crystal structure of MTSase derived from the hyperthermophilic archaeum Sulfolobus shibatae DSM5389 has been determined to 2.3 resolution by X-ray crystallography. Three invariant catalytic carboxylic amino acids in the -amylase family are found in MTSase at positions Asp241, Glu269 and Asp460 in the (/)8 domain.