Structure of a trapped radical transfer pathway within a ribonucleotide reductase holocomplex.
Science
; 368(6489): 424-427, 2020 04 24.
Article
em En
| MEDLINE
| ID: mdl-32217749
ABSTRACT
Ribonucleotide reductases (RNRs) are a diverse family of enzymes that are alone capable of generating 2'-deoxynucleotides de novo and are thus critical in DNA biosynthesis and repair. The nucleotide reduction reaction in all RNRs requires the generation of a transient active site thiyl radical, and in class I RNRs, this process involves a long-range radical transfer between two subunits, α and ß. Because of the transient subunit association, an atomic resolution structure of an active α2ß2 RNR complex has been elusive. We used a doubly substituted ß2, E52Q/(2,3,5)-trifluorotyrosine122-ß2, to trap wild-type α2 in a long-lived α2ß2 complex. We report the structure of this complex by means of cryo-electron microscopy to 3.6-angstrom resolution, allowing for structural visualization of a 32-angstrom-long radical transfer pathway that affords RNR activity.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ribonucleotídeo Redutases
/
Proteínas de Escherichia coli
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article