Ancestral amino acid residues were inferred for 3-isopropylmalate dehydrogenase (IPMDH), and were introduced into the enzyme of an extreme thermophile, Sulfolobus sp. strain 7. The thermostability of the mutant enzymes was compared with that of the wild type enzyme. At least five of the seven mutants tested showed higher thermal stability than the wild type IPMDH. The results are compatible with the hyperthermophilic universal ancestor hypothesis. The results also provide a new method for designing thermostable enzymes. The method only relies on the first dimensional structures of homologous enzymes that can be obtained from genetic databases. Study holds ProTherm entries: 23662, 23663, 23664, 23665, 23666, 23667, 23668, 23669 Extra Details: 0.5mM EDTA was added in the experiment archaeon (archaebacterium); common ancestor; Sulfolobus; 3-isopropylmalate dehydrogenase; protein stability
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:54 p.m.
|Number of data points||23|
|Proteins||3-isopropylmalate dehydrogenase ; 3-isopropylmalate dehydrogenase|
|Assays/Quantities/Protocols||Experimental Assay: activity ; Experimental Assay: Tm ; Derived Quantity: dTm|
|Libraries||Mutations for sequence GFTVALIQGDGIGPEIVSKSKRILAKINELYSLPIEYIEVEAGDRALARYGEALPKDSLKIIDKADIILKGPVGESAADVVVKLRQIYDMYANIRPAKSIPGIDTKYGNVDILIVRENTEDLYKGFEHIVSDGVAVGMKIITRFASERIAKVGLNFALRRRKKVTCVHKANVMRITDGLFAEACRSVLKGKVEYSEMYVDAAAANLVRNPQMFDVIVTENVYGDILSDEASQIAGSLGIAPSANIGDKKALFEPVHGAAFDIAGKNIGNPTAFLLSVSMMYERMYELSNDDRYIKASRALENAIYLVYKERKALTPDVGGNATTDDLINEIYNKLG|