Molecular switch-like regulation enables global subunit coordination in a viral ring ATPase.
Proc Natl Acad Sci U S A
; 115(31): 7961-7966, 2018 07 31.
Article
em En
| MEDLINE
| ID: mdl-30012596
ABSTRACT
Subunits in multimeric ring-shaped motors must coordinate their activities to ensure correct and efficient performance of their mechanical tasks. Here, we study WT and arginine finger mutants of the pentameric bacteriophage φ29 DNA packaging motor. Our results reveal the molecular interactions necessary for the coordination of ADP-ATP exchange and ATP hydrolysis of the motor's biphasic mechanochemical cycle. We show that two distinct regulatory mechanisms determine this coordination. In the first mechanism, the DNA up-regulates a single subunit's catalytic activity, transforming it into a global regulator that initiates the nucleotide exchange phase and the hydrolysis phase. In the second, an arginine finger in each subunit promotes ADP-ATP exchange and ATP hydrolysis of its neighbor. Accordingly, we suggest that the subunits perform the roles described for GDP exchange factors and GTPase-activating proteins observed in small GTPases. We propose that these mechanisms are fundamental to intersubunit coordination and are likely present in other ring ATPases.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Virais
/
Fagos Bacilares
/
Adenosina Trifosfatases
/
Modelos Biológicos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2018
Tipo de documento:
Article