Deoxyhypusine hydroxylase (DOHH)
The protein contains 302 amino acids for an estimated molecular weight of 32904 Da.
Catalyzes the hydroxylation of the N(6)-(4-aminobutyl)-L-lysine intermediate produced by deoxyhypusine synthase/DHPS on a critical lysine of the eukaryotic translation initiation factor 5A/eIF-5A. This is the second step of the post-translational modification of that lysine into an unusual amino acid residue named hypusine (PubMed:16533814, PubMed:16371467, PubMed:19706422). Hypusination is unique to mature eIF-5A factor and is essential for its function (By similarity). (updated: June 20, 2018)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
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The reference OMIM entry for this protein is 611262
Deoxyhypusine hydroxylase; dohh
Deoxyhypusine monooxygenase
Deoxyhypusine dioxygenase
Heat-like repeat-containing protein 1; hlrc1
DESCRIPTION
Deoxyhypusine hydroxylase (DOHH; EC 1.14.99.29) catalyzes the final step in the formation of the amino acid hypusine in eukaryotic initiation factor-5A (EIF5A; see 600187).CLONING
Posttranslational modification of a single lysine residue to hypusine in eIF5A requires deoxyhypusine synthase (DHPS; 600944) and deoxyhypusine hydroxylase. By screening a Saccharomyces cerevisiae GST-ORF library, Park et al. (2006) identified a novel gene, YJR070C, with deoxyhypusine hydroxylase activity. By database analysis, they identified a single homologous DOHH gene in eukaryotes, which are highly conserved from fungi to humans, but not in eubacteria or archaea. The human DOHH gene, which they authors designated HLRC1, shares 48% sequence identity with the yeast protein. DOHH contains 8 heat repeats organized in a symmetrical dyad connected by a variable region. It contains 2 potential metal coordination sites (one on each dyad), each composed of 2 strictly conserved his-glu motifs. By computer modeling, Park et al. (2006) found that the predicted structure of DOHH is different than that of the Fe(II)- and 2-oxoacid-dependent dioxygenases. CD spectroscopy of purified recombinant wildtype DOHH indicated an alpha-helix-rich protein (Kim et al., 2006), and site-directed mutagenesis showed that the alpha-helical structure of DOHH does not depend on the conserved his-glu motifs or metal binding.GENE FUNCTION
Park et al. (2006) demonstrated that purified recombinant yeast and human DOHH effectively catalyzed hydroxylation of the deoxyhypusine residue in the eIF5A intermediate. Overexpression of DHPS and DOHH along with eIF5A was necessary for overproduction of fully modified eIF5A, indicating that DHPS and DOHH are the rate-limiting factors in this process. An S. cerevisiae DOHH knockout strain produced only deoxyhypusine but no hypusine, indicating that a single gene is responsible for DOHH activity in this organism. Kim et al. (2006) determined that iron is the major metal in DOHH, with 2 moles of iron per mole of protein. In contrast to the wildtype holoenzyme, to which iron is bound, the DOHH apoenzyme, which lacks iron, showed a marked reduction in DOHH activity. Addition of ferrous ions restored activity. Substitution of alanine for any of the his or glu residues in the his-glu motifs resulted in complete lack of DOHH activity. Kim et al. (2006) showed that 6 of these mutants (H56A, H89A, E90A, H207A, H240A, and E241A) had markedly reduced iron content, and suggested that lack of iron binding affected activity. Kim et al. (2006) separated the DOHH holoenzyme and apoenzyme by native gel electrophoresis and found that the iron-bound holoenzyme migrated in a focused, fast-moving band that had DOHH activity, whereas the iron-free apoenzyme migrated more slowly in a diffuse fashion and lacked DOHH activity. Kim et al. (2006) suggested that iron binding induces the DOHH apoenzyme to undergo a conformational change to a more compact form. They showed that while DOHH binds both Fe(II) and Fe(III) ions, only Fe(II) ions induced activity. No other metal ions increased activity. Kim et al. (2006) concluded that Fe(II) is the active-site bound metal critical for DOHH catalysis and that the strictly conserved his-glu motifs are essential for iron binding and catalysis. They also suggested a binuclear iron-mediated reaction mechanism. ... More on the omim web site
July 2, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 611262 was added.