Biochemistry, Год журнала: 2024, Номер unknown
Опубликована: Дек. 9, 2024
Plants make pyrimidine base substitutions in organellar mRNAs through the action of sequence-specific nuclear-encoded enzymes. Pentatricopeptide repeat (PPR) proteins are essential for ensuring specificity, while enzymatic DYW domain is often present at C-terminus a PPR protein and dependent on variant possessing C-to-U and/or U-to-C RNA editing activities. Expression exogenous DYW-KP enzymes bacteria leads to modification RNAs suggestive changes. The modified could only be purified from interphase an acidic guanidinium thiocyanate-phenol-chloroform experiment. It was projected that stable RNA-enzyme cross-links form lysyl attack. In this study, examined dual U-to-C/C-to-U enzyme KP6 with conserved lysine residues substituted by alanine. A single found and, based crystal structures domains, would likely active site. Crystal also suggest can potentially ion pair catalytic glutamate critical editing. Mutation alanine greatly stimulated KP6. ∼319 Da adduct observed not detected U-to-C-deficient point mutant This work establishes role specifically activity but highlights secondary modulating formation inhibitory glutamate.
Язык: Английский