Unique fluorophores in the dimeric archaeal histones hMfB and hPyA1 reveal the impact of nonnative structure in a monomeric kinetic intermediate.

ABSTRACT: Homodimeric archaeal histones and heterodimeric eukaryotic histones share a conserved structure but fold through different kinetic mechanisms, with a correlation between faster folding/association rates and the population of kinetic intermediates. Wild-type hMfB (from Methanothermus fervidus) has no intrinsic fluorophores; Met35, which is Tyr in hyperthermophilic archaeal histones such as hPyA1 (from Pyrococcus strain GB-3A), was mutated to Tyr and Trp. Two Tyr-to-Trp mutants of hPyA1 were also characterized. All fluorophores were introduced into the long, central alpha-helix of the histone fold. Far-UV circular dichroism (CD) indicated that the fluorophores did not significantly alter the helical content of the histones. The equilibrium unfolding transitions of the histone variants were t

SUBMITTER: Stump MR 

PROVIDER: S-EPMC2222717 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature