We found that the CutA1 protein, from Pyrococcus horikoshii (PhCutA1), has an extremely high denaturation temperature (T(d)) of nearly 150 degrees C, which exceeds the highest record determined by DSC by about 30 degrees C. To elucidate the mechanism of the ultra-high stability of PhCutA1, we analyzed the crystal structures of CutA1 proteins from three different sources, P. horikoshii, Thermus thermophilus, and Escherichia coli, with different growth temperatures (98, 75, and 37 degrees C). This analysis revealed that the remarkably increased number of ion pairs in the monomeric structure contributes to the stabilization of the trimeric structure and plays an important role in enhancing the T(d), up to 150 degrees C, for PhCutA1. Study holds ProTherm entries: 22918, 22919, 22920 Extra Details: Protein stability; DSC; Hyperthermophile; Heat denaturation; Ion pairs; Protein structure
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:54 p.m.
|Number of data points||3|
|Proteins||Divalent-cation tolerance protein CutA ; Divalent-cation tolerance protein CutA ; Divalent-cation tolerance protein CutA ; Divalent-cation tolerance protein CutA|
|Assays/Quantities/Protocols||Experimental Assay: Tm details:Additives EDTA (2 mM),, pH:9.0, buffers:Gly-KOH: 50 mM ; Experimental Assay: Tm details:Additives , buffers:potassium phosphate: 50 mM, pH:7.0|
|Libraries||Mutations for sequence MIIVYTTFPDWESAEKVVKTLLKERMIACANLREHRAFYWWEGKIEEDKEVGAILKTREDLWEELKERIKELHPYDVPAIIRIDVDDVNEDYLKWLIEETKK ; Mutations for sequence MEEVVLITVPSEEVARTIAKALVEERLAACVNIVPGLTSIYRWQGEVVEDQELLLLVKTTTHAFPKLKERVKALHPYTVPEIVALPIAEGNREYLDWLRENTG|