Eleanor Bagg - Kinetic rationale for selectivity toward N- and C-terminal oxygen-dependent degradation domain substrates mediated by a loop region of hypoxia-inducible factor prolyl hydroxylases

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      Publication Details (including relevant citation   information):

      J Biol Chem. 2008 283(7) 3808-15

      Abstract:

      Hydroxylation of two conserved prolyl residues in the N- and   C-terminal  oxygen-dependent degradation domains (NODD and   CODD) of the  alpha-subunit of hypoxia-inducible factor   (HIF) signals for its  degradation via the   ubiquitin-proteasome pathway. In human cells, three  prolyl   hydroxylases (PHDs 1-3) belonging to the Fe(II) and    2-oxoglutarate (2OG)-dependent oxygenase family catalyze   prolyl  hydroxylation with differing selectivity for CODD   and NODD. Sequence  analysis of the catalytic domains of the   PHDs in the light of crystal  structures for PHD2, and   results for other 2OG oxygenases, suggested  that either the   C-terminal region or a loop linking two beta-strands  (beta2   and beta3 in human PHD2) are important in determining   substrate  selectivity. Mutation analyses on PHD2 revealed   that the beta2beta3 loop  is a major determinant in   conferring selectivity for CODD over NODD  peptides. A   chimeric PHD in which the beta2beta3 loop of PHD2 was    replaced with that of PHD3 displayed an almost complete   selectivity for  CODD (in competition experiments), as   observed for wild-type PHD3. CODD  was observed to bind much   more tightly to this chimeric protein than the  wild type   PHD2 catalytic domain.

      Address (URL): http://www.jbc.org/content/283/7/3808.long