Diphthamide
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| IUPAC name
2-Amino-3-[2-(3-carbamoyl-3-trimethylammonio-propyl)-3H-imidazol-4-yl]propanoate
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C13H23N5O3 | |
| Molar mass | 297.354 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Diphthamide is a post-translationally modified histidine amino acid found in archaeal and eukaryotic elongation factor 2 (eEF-2).
Dipthamide is named after the toxin produced by the bacterium Corynebacterium diphtheriae, which targets diphthamide.[1] Besides this toxin, it is also targeted by exotoxin A from Pseudomonas aeruginosa.[1][2] It is the only target of these toxins.[2]
Structure and biosynthesis
[edit]Diphthamide is proposed to be a 2-[3-carboxyamido-3-(trimethylammonio)propyl]histidine. Though this structure has been confirmed by X-ray crystallography, its stereochemistry is uncertain.[1][3]
Diphthamide is biosynthesized from histidine and S-adenosyl methionine (SAM).[1] The side chain bound to imidazole group and all methyl groups come from SAM. The whole synthesis takes place in three steps:[1]
- transfer of 3-amino-3-carboxypropyl group from SAM
- transfer of three methyl groups from SAM – synthesis of diphtine
- amidation – synthesis of diphthamide
In eukaryotes, this biosynthetic pathway contains a total of 7 genes (Dph1-7).[1]
Biological function
[edit]Diphthamide ensures translation fidelity.[1]
The presence or absence of diphthamide is known to affect NF-κB or death receptor pathways.[4]
References
[edit]- ^ a b c d e f g Su X, Lin Z, Lin H (2013-11-01). "The biosynthesis and biological function of diphthamide". Critical Reviews in Biochemistry and Molecular Biology. 48 (6): 515–521. doi:10.3109/10409238.2013.831023. PMC 4280834. PMID 23971743.
- ^ a b Liu S, Wiggins JF, Sreenath T, Kulkarni AB, Ward JM, Leppla SH (May 2006). "Dph3, a small protein required for diphthamide biosynthesis, is essential in mouse development". Molecular and Cellular Biology. 26 (10): 3835–3841. doi:10.1128/MCB.26.10.3835-3841.2006. PMC 1488998. PMID 16648478.
- ^ Jørgensen R, Merrill AR, Andersen GR (February 2006). "The life and death of translation elongation factor 2". Biochemical Society Transactions. 34 (Pt 1): 1–6. doi:10.1042/BST20060001. PMID 16246167.
- ^ Stahl S, da Silva Mateus Seidl AR, Ducret A, Kux van Geijtenbeek S, Michel S, Racek T, et al. (August 2015). "Loss of diphthamide pre-activates NF-κB and death receptor pathways and renders MCF7 cells hypersensitive to tumor necrosis factor". Proceedings of the National Academy of Sciences of the United States of America. 112 (34): 10732–10737. Bibcode:2015PNAS..11210732S. doi:10.1073/pnas.1512863112. PMC 4553792. PMID 26261303.