| Structural highlights
3kem is a 2 chain structure with sequence from Ecoli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , |
| Related: | 3f7t, 3dnf, 3ke8, 3ke9, 3kef, 3kel |
| Gene: | b0029, ispH, JW0027, lytB, yaaE (ECOLI) |
| Activity: | 4-hydroxy-3-methylbut-2-enyl diphosphate reductase, with EC number 1.17.1.2 |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Function
[ISPH_ECOLI] Converts 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate into isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Is also involved in penicillin tolerance and control of the stringent response. Seems to directly or indirectly interact with RelA to maintain it in an inactive form during normal growth.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) represent the two central intermediates in the biosynthesis of isoprenoids. The recently discovered deoxyxylulose 5-phosphate pathway generates a mixture of IPP and DMAPP in its final step by reductive dehydroxylation of 1-hydroxy-2-methyl-2-butenyl 4-diphosphate. This conversion is catalyzed by IspH protein comprising a central iron-sulfur cluster as electron transfer cofactor in the active site. The five crystal structures of IspH in complex with substrate, converted substrate, products and PP(i) reported in this article provide unique insights into the mechanism of this enzyme. While IspH protein crystallizes with substrate bound to a [4Fe-4S] cluster, crystals of IspH in complex with IPP, DMAPP or inorganic pyrophosphate feature [3Fe-4S] clusters. The IspH:substrate complex reveals a hairpin conformation of the ligand with the C(1) hydroxyl group coordinated to the unique site in a [4Fe-4S] cluster of aconitase type. The resulting alkoxide complex is coupled to a hydrogen-bonding network, which serves as proton reservoir via a Thr167 proton relay. Prolonged x-ray irradiation leads to cleavage of the C(1)-O bond (initiated by reducing photo electrons). The data suggest a reaction mechanism involving a combination of Lewis-acid activation and proton coupled electron transfer. The resulting allyl radical intermediate can acquire a second electron via the iron-sulfur cluster. The reaction may be terminated by the transfer of a proton from the beta-phosphate of the substrate to C(1) (affording DMAPP) or C(3) (affording IPP).
Probing the reaction mechanism of IspH protein by x-ray structure analysis.,Grawert T, Span I, Eisenreich W, Rohdich F, Eppinger J, Bacher A, Groll M Proc Natl Acad Sci U S A. 2010 Jan 19;107(3):1077-81. Epub 2009 Dec 28. PMID:20080550[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Grawert T, Rohdich F, Span I, Bacher A, Eisenreich W, Eppinger J, Groll M. Structure of active IspH enzyme from Escherichia coli provides mechanistic insights into substrate reduction. Angew Chem Int Ed Engl. 2009;48(31):5756-9. PMID:19569147 doi:10.1002/anie.200900548
- ↑ Grawert T, Span I, Eisenreich W, Rohdich F, Eppinger J, Bacher A, Groll M. Probing the reaction mechanism of IspH protein by x-ray structure analysis. Proc Natl Acad Sci U S A. 2010 Jan 19;107(3):1077-81. Epub 2009 Dec 28. PMID:20080550
- ↑ Span I, Grawert T, Bacher A, Eisenreich W, Groll M. Crystal Structures of Mutant IspH Proteins Reveal a Rotation of the Substrate's Hydroxymethyl Group during Catalysis. J Mol Biol. 2011 Nov 23. PMID:22137895 doi:10.1016/j.jmb.2011.11.033
- ↑ Grawert T, Span I, Eisenreich W, Rohdich F, Eppinger J, Bacher A, Groll M. Probing the reaction mechanism of IspH protein by x-ray structure analysis. Proc Natl Acad Sci U S A. 2010 Jan 19;107(3):1077-81. Epub 2009 Dec 28. PMID:20080550
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