title: Crystal structures of protein glutaminase and its pro forms converted into enzyme-substrate complex.
abstract: Protein glutaminase, which converts a protein glutamine residue to a glutamate residue, is expected to be useful as a new food-processing enzyme. The crystal structures of the mature and pro forms of the enzyme were refined at 1.15 and 1.73 Å resolution, respectively. The overall structure of the mature enzyme has a weak homology to the core domain of human transglutaminase-2. The catalytic triad (Cys-His-Asp) common to transglutaminases and cysteine proteases is located in the bottom of the active site pocket. The structure of the recombinant pro form shows that a short loop between S2 and S3 in the proregion covers and interacts with the active site of the mature region, mimicking the protein substrate of the enzyme. Ala-47 is located just above the pocket of the active site. Two mutant structures (A47Q-1 and A47Q-2) refined at 1.5 Å resolution were found to correspond to the enzyme-substrate complex and an S-acyl intermediate. Based on these structures, the catalytic mechanism of protein glutaminase is proposed.
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Hashizume
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Maki
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Mizutani
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takahashi
authors.affiliation: Gifu R&D Center, Amano Enzyme Incorporated, 1-6 Technoplaza, Kakamigahara, Gifu 509-0108, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsubara
authors.affiliation: Gifu R&D Center, Amano Enzyme Incorporated, 1-6 Technoplaza, Kakamigahara, Gifu 509-0108, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Sugita
authors.affiliation: Gifu R&D Center, Amano Enzyme Incorporated, 1-6 Technoplaza, Kakamigahara, Gifu 509-0108, Japan.
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Sato
authors.affiliation: Gifu R&D Center, Amano Enzyme Incorporated, 1-6 Technoplaza, Kakamigahara, Gifu 509-0108, Japan.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan. Electronic address: mikami@kais.kyoto-u.ac.jp.
authors.forename: Bunzo
authors.initials: B
authors.lastname: Mikami
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D020134:Catalytic Domain; D045247:Chryseobacterium / Q000201:enzymology*; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D057056:Cysteine Proteases / Q000737:chemistry; D005972:Glutaminase / Q000737:chemistry*; D005973:Glutamine / Q000737:chemistry; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011392:Proline / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D011503:Transglutaminases / Q000737:chemistry
chemical_list: D005973:Glutamine; D011392:Proline; D011503:Transglutaminases; D057056:Cysteine Proteases; D005972:Glutaminase