Three-dimensional structure of tyrosine phenol-lyase

A A Antson, T V Demidkina, P Gollnick, Z Dauter, R L von Tersch, J Long, S N Berezhnoy, R S Phillips, E H Harutyunyan, K S Wilson

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Tyrosine phenol-lyase (EC 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.

Original languageEnglish
Pages (from-to)4195-206
Number of pages12
Issue number16
Publication statusPublished - 27 Apr 1993


  • Amino Acid Sequence
  • Apoenzymes/chemistry
  • Base Sequence
  • Binding Sites
  • Citrobacter/enzymology
  • Citrobacter freundii/enzymology
  • Cloning, Molecular
  • Genes, Bacterial
  • Genomic Library
  • Macromolecular Substances
  • Models, Molecular
  • Models, Structural
  • Molecular Sequence Data
  • Peptide Fragments/chemistry
  • Protein Structure, Secondary
  • Recombinant Proteins/chemistry
  • Sequence Homology, Amino Acid
  • Tyrosine Phenol-Lyase/chemistry

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