Thermal stability and DNA binding activity of a variant form of the Sso7d protein from the archeon Sulfolobus solfataricus truncated at leucine 54.


Abstract

Sso7d is a 62-residue, basic protein from the hyperthermophilic archaeon Sulfolobus solfataricus. Around neutral pH, it exhibits a denaturation temperature close to 100 degrees C and a non-sequence-specific DNA binding activity. Here, we report the characterization by circular dichroism and fluorescence measurements of a variant form of Sso7d truncated at leucine 54 (L54Delta). It is shown that L54Delta has a folded conformation at neutral pH and that its thermal unfolding is a reversible process, represented well by the two-state N <=> D transition model, with a denaturation temperature of 53 degrees C. Fluorescence titration experiments indicate that L54Delta binds tightly to calf thymus DNA, even though the binding parameters are smaller than those of the wild-type protein. Therefore, the truncation of eight residues at the C-terminus of Sso7d markedly affects the thermal stability of the protein, which nevertheless retains a folded structure and DNA binding activity. Study holds ProTherm entries: 16475, 16476, 16477, 16478, 16479, 16480, 16481 Extra Details: hyperthermophilic archaeon; non-sequence-specific; DNA binding activity; thermal stability

Submission Details

ID: vgp7BKRy3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:48 p.m.

Version: 1

Publication Details
Shehi E;Granata V;Del Vecchio P;Barone G;Fusi P;Tortora P;Graziano G,Biochemistry (2003) Thermal stability and DNA binding activity of a variant form of the Sso7d protein from the archeon Sulfolobus solfataricus truncated at leucine 54. PMID:12846585
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