XB-ART-11609J Biol Chem January 28, 2000; 275 (4): 2491-8.
Sequential MCM/P1 subcomplex assembly is required to form a heterohexamer with replication licensing activity.
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.
PubMed ID: 10644704
PMC ID: PMC3626232
Article link: J Biol Chem
Species referenced: Xenopus
Genes referenced: mmut rlf
References [+] :
Adachi, A globular complex formation by Nda1 and the other five members of the MCM protein family in fission yeast. 1997, Pubmed