We have combined three mutations previously shown to stabilize lambda repressor against thermal denaturation. Two of these mutations are in helix 3, where Gly-46 and Gly-48 have been replaced by alanines [Hecht, M. H., et al. (1986) Proteins: Struct., Funct., Genet. 1, 43-46]. The other mutation, which replaces Tyr-88 with cysteine, allows the protein to form an intersubunit disulfide bond [Sauer, R. T., et al. (1986) Biochemistry 25, 5992-5998]. Calorimetric measurements show that the two alanine substitutions stabilize repressor by about 8 degrees C, that the disulfide bond stabilizes repressor by about 8 degrees C, and that the triple mutant is 16 degrees C more stable than wild-type repressor. Study holds ProTherm entries: 3928, 3929, 3930, 3931, 14253, 14254, 14255 Extra Details: thermostable mutations; cysteine; alanine substitutions;,disulfide bond
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:23 p.m.
|Number of data points||19|
|Proteins||Repressor protein cI ; Repressor protein cI|
|Assays/Quantities/Protocols||Experimental Assay: ddG ; Experimental Assay: dHcal ; Experimental Assay: Tm ; Experimental Assay: dHvH ; Derived Quantity: dTm|
|Libraries||Mutations for sequence STKKKPLTQEQLEDARRLKAIYEKKKNELGLSQESVADKMGMGQSGVGALFNGINALNAYNAALLAKILKVSVEEFSPSIAREIYEMYEAVS|