Random mutagenesis on thermophilic 3-isopropylmalate dehydrogenases (IPMDH; EC 188.8.131.52) produced mutant enzymes which adapt to low temperatures. These mutants had higher activity at lower temperatures than the wild-type enzyme without losing high thermostability. Here we report three structures of the mutants of Thermus thermophilus IPMDH determined by X-ray diffraction which was adapted to a low-temperature environment. Two of them have unstable coenzyme binding states and the other one probably has a stable substrate binding state. The present research suggests that the adaptation is correlated with the binding of either coenzyme or the substrate. Study holds ProTherm entries: 10880, 10881, 10882, 10883 Extra Details: cold-adapted mutants; 3-isopropylmalate dehydrogenase;,thermal stability; Thermus thermophilus; structural analysis
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:41 p.m.
|Number of data points||4|
|Proteins||3-isopropylmalate dehydrogenase ; 3-isopropylmalate dehydrogenase|
|Assays/Quantities/Protocols||Experimental Assay: Tm|
|Libraries||Mutations for sequence MKVAVLPGDGIGPEVTEAALKVLRALDEAEGLGLAYEVFPFGGAAIDAFGEPFPEPTRKGVEEAEAVLLGSVGGPKWDGLPRKIRPETGLLSLRKSQDLFANLRPAKVFPGLERLSPLKEEIARGVDVLIVRELTGGIYFGEPRGMSEAEAWNTERYSKPEVERVARVAFEAARKRRKHVVSVDKANVLEVGEFWRKTVEEVGRGYPDVALEHQYVDAMAMHLVRSPARFDVVVTGNIFGDILSDLASVLPGSLGLLPSASLGRGTPVFEPVHGSAPDIAGKGIANPTAAILSAAMMLEHAFGLVELARKVEDAVAKALLETPPPDLGGSAGTEAFTATVLRHLA|