title: Three-dimensional structure of tyrosine phenol-lyase.
abstract: Tyrosine phenol-lyase (EC 4.1.99.2) from Citrobacter freundii has been cloned and the primary sequence deduced from the DNA sequence. From the BrCN digest of the NaBH4-reduced holoenzyme, five peptides were purified and sequenced. The amino acid sequences of the peptides agreed with the corresponding parts of the tyrosine phenol-lyase sequence obtained from the gene structure. K257 is the pyridoxal 5'-phosphate binding residue. Assisted by the sequence data, the crystal structure of apotyrosine phenol-lyase, a pyridoxal 5'-phosphate-dependent enzyme, has been refined to an R-factor of 16.2% at 2.3-A resolution using synchrotron radiation diffraction data. The tetrameric molecule has 222 symmetry, with one of the axes coincident with the crystallographic 2-fold symmetry axis of the crystal which belongs to the space group P2(1)2(1)2 with a = 76.0 A, b = 138.3 A, and c = 93.5 A. Each subunit comprises 14 alpha-helices and 16 beta-strands, which fold into a small and a large domain. The coenzyme-binding lysine residue is located at the interface between the large and small domains of one subunit and the large domain of a crystallographically related subunit. The fold of the large, pyridoxal 5'-phosphate binding domain and the location of the active site are similar to that found in aminotransferases. Most of the residues which participate in binding of pyridoxal 5'-phosphate in aminotransferases are conserved in the structure of tyrosine phenol-lyase. Two dimers of tyrosine phenol-lyase, each of which has a domain architecture similar to that found in aspartate aminotransferases, are bound together through a hydrophobic cluster in the center of the molecule and intertwined N-terminal arms.
authors.affiliation: Shubnikov Institute of Crystallography, Russian Academy of Sciences, Moscow.
authors.forename: A A
authors.initials: AA
authors.lastname: Antson
authors.forename: T V
authors.initials: TV
authors.lastname: Demidkina
authors.forename: P
authors.initials: P
authors.lastname: Gollnick
authors.forename: Z
authors.initials: Z
authors.lastname: Dauter
authors.forename: R L
authors.initials: RL
authors.lastname: von Tersch
authors.forename: J
authors.initials: J
authors.lastname: Long
authors.forename: S N
authors.initials: SN
authors.lastname: Berezhnoy
authors.forename: R S
authors.initials: RS
authors.lastname: Phillips
authors.forename: E H
authors.initials: EH
authors.lastname: Harutyunyan
authors.forename: K S
authors.initials: KS
authors.lastname: Wilson
mesh_terms: D000595:Amino Acid Sequence; D001051:Apoenzymes / Q000737:chemistry; D001483:Base Sequence; D001665:Binding Sites; D002954:Citrobacter / Q000201:enzymology; D016971:Citrobacter freundii / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D015698:Genomic Library; D046911:Macromolecular Substances; D008958:Models, Molecular; D008961:Models, Structural; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014447:Tyrosine Phenol-Lyase / Q000737:chemistry* / Q000235:genetics*
chemical_list: D001051:Apoenzymes; D046911:Macromolecular Substances; D010446:Peptide Fragments; D011994:Recombinant Proteins; D014447:Tyrosine Phenol-Lyase