Crystal structure of human ornithine decarboxylase at 2.1 Å resolution: Structural insights to antizyme binding

Jeffrey J. Almrud, Marcos A. Oliveira, Andrew D. Kern, Nick V. Grishin, Margaret A. Phillips, Marvin L. Hackert

Research output: Contribution to journalArticle

117 Scopus citations


The polyamines spermidine and spermine are ubiquitous and required for cell growth and differentiation in eukaryotes. Ornithine decarboxylase (ODC, EC performs the first step in polyamine biosynthesis, the decarboxylation of omithine to putrescine. Elevated polyamine levels can lead to down-regulation of ODC activity by enhancing the translation of antizyme mRNA, resulting in subsequent binding of antizyme to ODC monomers which targets ODC for proteolysis by the 26S proteasome. The crystal structure of ornithine decarboxylase from human liver has been determined to 2.1 Å resolution by molecular replacement using truncated mouse ODC (Δ425-461) as the search model and refined to a crystallographic R-factor of 21.2% and an R-free value of 28.8%. The human ODC model includes several regions that are disordered in the mouse ODC crystal structure, including one of two C-terminal basal degradation elements that have been demonstrated to independently collaborate with antizyme binding to target ODC for degradation by the 26S proteasome. The crystal structure of human ODC suggests that the C terminus, which contains basal degradation elements necessary for antizyme-induced proteolysis, is not buried by the structural core of homodimeric ODC as previously proposed. Analysis of the solvent-accessible surface area, surface electrostatic potential, and the conservation of primary sequence between human ODC and Trypanosoma brucei ODC provides clues to the identity of potential protein-binding-determinants in the putative antizyme binding element in human ODC.

Original languageEnglish (US)
Pages (from-to)7-16
Number of pages10
JournalJournal of Molecular Biology
Issue number1
Publication statusPublished - Jan 7 2000



  • Antizyme
  • Decarboxylase
  • Ornithine
  • Polyamines
  • Pyridoxal-5'-phosphate

ASJC Scopus subject areas

  • Virology

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