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Title: Human Deoxyhypusine Hydroxylase, an Enzyme Involved in Regulating Cell Growth, Activates O2 with a Nonheme Diiron Center

Abstract

Deoxyhypusine hydroxylase is the key enzyme in the biosynthesis of hypusine containing eukaryotic translation initiation factor 5A (eIF5A), which plays an essential role in the regulation of cell proliferation. Recombinant human deoxyhypusine hydroxylase (hDOHH) has been reported to have oxygen- and iron-dependent activity, an estimated iron/holoprotein stoichiometry of 2, and a visible band at 630 nm responsible for the blue color of the as-isolated protein. EPR, Moessbauer, and XAS spectroscopic results presented herein provide direct spectroscopic evidence that hDOHH has an antiferromagnetically coupled diiron center with histidines and carboxylates as likely ligands, as suggested by mutagenesis experiments. Resonance Raman experiments show that its blue chromophore arises from a (e-1,2-peroxo)diiron(III) center that forms in the reaction of the reduced enzyme with O2, so the peroxo form of hDOHH is unusually stable. Nevertheless we demonstrate that it can carry out the hydroxylation of the deoxyhypusine residue present in the elF5A substrate. Despite a lack of sequence similarity, hDOHH has a nonheme diiron active site that resembles both in structure and function those found in methane and toluene monooxygenases, bacterial and mammalian ribonucleotide reductases, and stearoyl acyl carrier protein ?9-desaturase from plants, suggesting that the oxygen-activating diiron motif is a solution arrived atmore » by convergent evolution. Notably, hDOHH is the only example thus far of a human hydroxylase with such a diiron active site.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
980245
Report Number(s):
BNL-93163-2010-JA
Journal ID: ISSN 0027-8424; PNASA6; TRN: US201015%%1630
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 106; Journal Issue: 35; Journal ID: ISSN 0027-8424
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BIOSYNTHESIS; CELL PROLIFERATION; COLOR; ENZYMES; HYDROXYLASES; HYDROXYLATION; METHANE; MUTAGENESIS; OXIDOREDUCTASES; OXYGEN; PROTEINS; REGULATIONS; RESIDUES; RESONANCE; STOICHIOMETRY; TOLUENE; national synchrotron light source

Citation Formats

Vu, V, Emerson, J, Martinho, M, Kim, Y, Munck, E, Park, M, and Que, Jr., L. Human Deoxyhypusine Hydroxylase, an Enzyme Involved in Regulating Cell Growth, Activates O2 with a Nonheme Diiron Center. United States: N. p., 2009. Web. doi:10.1073/pnas.0904553106.
Vu, V, Emerson, J, Martinho, M, Kim, Y, Munck, E, Park, M, & Que, Jr., L. Human Deoxyhypusine Hydroxylase, an Enzyme Involved in Regulating Cell Growth, Activates O2 with a Nonheme Diiron Center. United States. https://doi.org/10.1073/pnas.0904553106
Vu, V, Emerson, J, Martinho, M, Kim, Y, Munck, E, Park, M, and Que, Jr., L. Thu . "Human Deoxyhypusine Hydroxylase, an Enzyme Involved in Regulating Cell Growth, Activates O2 with a Nonheme Diiron Center". United States. https://doi.org/10.1073/pnas.0904553106.
@article{osti_980245,
title = {Human Deoxyhypusine Hydroxylase, an Enzyme Involved in Regulating Cell Growth, Activates O2 with a Nonheme Diiron Center},
author = {Vu, V and Emerson, J and Martinho, M and Kim, Y and Munck, E and Park, M and Que, Jr., L},
abstractNote = {Deoxyhypusine hydroxylase is the key enzyme in the biosynthesis of hypusine containing eukaryotic translation initiation factor 5A (eIF5A), which plays an essential role in the regulation of cell proliferation. Recombinant human deoxyhypusine hydroxylase (hDOHH) has been reported to have oxygen- and iron-dependent activity, an estimated iron/holoprotein stoichiometry of 2, and a visible band at 630 nm responsible for the blue color of the as-isolated protein. EPR, Moessbauer, and XAS spectroscopic results presented herein provide direct spectroscopic evidence that hDOHH has an antiferromagnetically coupled diiron center with histidines and carboxylates as likely ligands, as suggested by mutagenesis experiments. Resonance Raman experiments show that its blue chromophore arises from a (e-1,2-peroxo)diiron(III) center that forms in the reaction of the reduced enzyme with O2, so the peroxo form of hDOHH is unusually stable. Nevertheless we demonstrate that it can carry out the hydroxylation of the deoxyhypusine residue present in the elF5A substrate. Despite a lack of sequence similarity, hDOHH has a nonheme diiron active site that resembles both in structure and function those found in methane and toluene monooxygenases, bacterial and mammalian ribonucleotide reductases, and stearoyl acyl carrier protein ?9-desaturase from plants, suggesting that the oxygen-activating diiron motif is a solution arrived at by convergent evolution. Notably, hDOHH is the only example thus far of a human hydroxylase with such a diiron active site.},
doi = {10.1073/pnas.0904553106},
url = {https://www.osti.gov/biblio/980245}, journal = {Proceedings of the National Academy of Sciences of the United States of America},
issn = {0027-8424},
number = 35,
volume = 106,
place = {United States},
year = {2009},
month = {1}
}