title: Crystal structure of an acetyl esterase complexed with acetate ion provides insights into the catalytic mechanism.
abstract: We previously reported the crystal structure of an acetyl esterase (TcAE206) belonging to carbohydrate esterase family 3 from Talaromyces cellulolyticus. In this study, we solved the crystal structure of an S10A mutant of TcAE206 complexed with an acetate ion. The acetate ion was stabilized by three hydrogen bonds in the oxyanion hole instead of a water molecule as in the structure of wild-type TcAE206. Furthermore, the catalytic triad residue His182 moved 0.8 Å toward the acetate ion upon substrate entering the active site, suggesting that this movement is necessary for completion of the catalytic reaction.
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Uechi
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Kamachi
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Hironaga
authors.initials: H
authors.lastname: Akita
authors.affiliation: Biomedical Research Institute (BMD), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka, 563-8577, Japan.
authors.forename: Shouhei
authors.initials: S
authors.lastname: Mine
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan. Electronic address: masa-watanabe@aist.go.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000115:Acetylesterase / Q000737:chemistry*; D000595:Amino Acid Sequence; D002384:Catalysis; D018360:Crystallography, X-Ray; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D032901:Talaromyces / Q000201:enzymology
chemical_list: D000085:Acetates; D000115:Acetylesterase
keywords: Acetyl esterase; Carbohydrate esterase family 3; Catalytic triad; Oxyanion hole; SGNH-hydrolase; Talaromyces cellulolyticus