title: Crystal structure of Bifidobacterium Longum phosphoketolase; key enzyme for glucose metabolism in Bifidobacterium.
abstract: The crystal structure of Bifidobacterium longum phosphoketolase, a thiamine diphosphate (TPP) dependent enzyme, has been determined at 2.2A resolution. The enzyme is a dimer with the active sites located at the interface between the two identical subunits with molecular mass of 92.5 kDa. The bound TPP is almost completely shielded from solvent except for the catalytically important C2-carbon of the thiazolium ring, which can be accessed by a substrate sugar through a narrow funnel-shaped channel. In silico docking studies of B. longum phosphoketolase with its substrate enable us to propose a model for substrate binding.
authors.affiliation: Institute of Life Sciences, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki, Japan.
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Takahashi
authors.forename: Uno
authors.initials: U
authors.lastname: Tagami
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Shimba
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Kashiwagi
authors.forename: Kohki
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Ei-ichiro
authors.initials: E
authors.lastname: Suzuki
mesh_terms: D000446:Aldehyde-Lyases / Q000737:chemistry*; D001644:Bifidobacterium / Q000201:enzymology*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D005947:Glucose / Q000378:metabolism*; D008958:Models, Molecular; D011487:Protein Conformation; D013379:Substrate Specificity; D013835:Thiamine Pyrophosphate / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000446:Aldehyde-Lyases; C022367:phosphoketolase; D005947:Glucose; D013835:Thiamine Pyrophosphate