Sequential MCM/P1 subcomplex assembly is required to form a heterohexamer with replication licensing activity.
J Biol Chem
; 275(4): 2491-8, 2000 Jan 28.
Article
en En
| MEDLINE
| ID: mdl-10644704
Replication licensing factor (RLF) is a multiprotein complex involved in ensuring that chromosomal DNA replicates only once in a single cell cycle. It comprises two components, termed RLF-M and RLF-B. Purified RLF-M consists of a mixture of complexes containing all six members of the MCM/P1 family of minichromosome maintenance proteins. The precise composition of these different complexes and their contribution to RLF-M activity has been unclear. Here we show that in Xenopus extracts, MCM/P1 proteins mainly form heterohexamers containing each of the six proteins. This heterohexamer is readily split into subcomplexes, whose interactions and subunit composition we characterize in detail. We show for the first time an ordered multistep assembly pathway by which the heterohexamer can be reformed from the subcomplexes. Importantly, this novel pathway is essential for DNA replication, since only the full heterohexamer can bind productively to chromatin and provide RLF-M activity.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Ciclo Celular
/
Proteínas de Unión al ADN
/
Replicación del ADN
Idioma:
En
Revista:
J Biol Chem
Año:
2000
Tipo del documento:
Article
País de afiliación:
Reino Unido
Pais de publicación:
Estados Unidos