1txg
Structure of glycerol-3-phosphate dehydrogenase from Archaeoglobus fulgidus
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| , resolution 1.70Å | |||||||
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| Ligands: | , and | ||||||
| Activity: | Glycerol-3-phosphate dehydrogenase (NAD(P)(+)), with EC number 1.1.1.94 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
NAD(+)-dependent glycerol-3-phosphate dehydrogenase (G3PDH) is generally absent in archaea, because archaea, unlike eukaryotes and eubacteria, utilize glycerol-1-phosphate instead of glycerol-3-phosphate for the biosynthesis of membrane lipids. Surprisingly, the genome of the hyperthermophilic archaeon Archaeoglobus fulgidus comprises a G3PDH ortholog, gpsA, most likely due to horizontal gene transfer from a eubacterial organism. Biochemical characterization proved G3PDH-like activity of the recombinant gpsA gene product. However, unlike other G3PDHs, the up to 85 degrees C thermostable A. fulgidus G3PDH exerted a 15-fold preference for NADPH over NADH. The A. fulgidus G3PDH bears the hallmarks of adaptation to halotolerance and thermophilicity, because its 1.7-A crystal structure showed a high surface density for negative charges and 10 additional intramolecular salt bridges compared to a mesophilic G3PDH structure. Whereas all amino acid residues required for dihydroxyacetone phosphate binding and reductive catalysis are highly conserved, the binding site for the adenine moiety of the NAD(P) cosubstrate shows a structural variation that reflects the observed NADPH preference, for example, by a putative salt bridge between R49 and the 2'-phosphate.
About this StructureAbout this Structure
1TXG is a Single protein structure of sequence from Archaeoglobus fulgidus. Full crystallographic information is available from OCA.
ReferenceReference
Structural and functional analysis of the gpsA gene product of Archaeoglobus fulgidus: a glycerol-3-phosphate dehydrogenase with an unusual NADP+ preference., Sakasegawa S, Hagemeier CH, Thauer RK, Essen LO, Shima S, Protein Sci. 2004 Dec;13(12):3161-71. PMID:15557260
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