The Role of the Arginine in the Conserved N-Terminal Domain RLFDQxFG Motif of Human Small Heat Shock Proteins HspB1, HspB4, HspB5, HspB6, and HspB8.

ABSTRACT: Although the N-terminal domain of vertebrate small heat shock proteins (sHsp) is poorly conserved, it contains a core motif preserved in many members of the sHsp family. The role of this RLFDQxFG motif remains elusive. We analyzed the specific role of the first arginine residue of this conserved octet sequence in five human sHsps (HspB1, HspB4, HspB5, HspB6, and HspB8). Substitution of this arginine with an alanine induced changes in thermal stability and/or intrinsic fluorescence of the related HspB1 and HspB8, but yielded only modest changes in the same biophysical properties of HspB4, HspB5, and HspB6 which together belong to another clade of vertebrate sHsps. Removal of the positively charged Arg side chain resulted in destabilization of the large oligomers of HspB1 and formation of sm

SUBMITTER: Shatov VM 

PROVIDER: S-EPMC6073470 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature