Scaling Catalytic Contributions of Small Self-Cleaving Ribozymes.
Angew Chem Weinheim Bergstr Ger
; 134(41): e202207590, 2022 Oct 10.
Article
em En
| MEDLINE
| ID: mdl-38505292
ABSTRACT
Nucleolytic ribozymes utilize general acid-base catalysis to perform phosphodiester cleavage. In most ribozyme classes, a conserved active site guanosine is positioned to act as general base, thereby activating the 2'-OH group to attack the scissile phosphate (γ-catalysis). Here, we present an atomic mutagenesis study for the pistol ribozyme class. Strikingly, "general base knockout" by replacement of the guanine N1 atom by carbon results in only 2.7-fold decreased rate. Therefore, the common view that γ-catalysis critically depends on the N1 moiety becomes challenged. For pistol ribozymes we found that γ-catalysis is subordinate in overall catalysis, made up by two other catalytic factors (α and δ). Our approach allows scaling of the different catalytic contributions (α, ß, γ, δ) with unprecedented precision and paves the way for a thorough mechanistic understanding of nucleolytic ribozymes with active site guanines.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Weinheim Bergstr Ger
Assunto da revista:
BIOFISICA
/
QUIMICA
Ano de publicação:
2022
Tipo de documento:
Article