Intersubunit allosteric communication mediated by a conserved loop in the MCM helicase.

The minichromosome maintenance (MCM) helicase is the presumptive replicative helicase in archaea and eukaryotes. The archaeal homomultimeric MCM has a two-tier structure. One tier contains the AAA+ motor domains of the proteins, and these are the minimal functional helicase domains.

Transcript analysis of dinoflagellate plastid gene minicircles.

The dinoflagellate chloroplast genome is fragmented into a number of plasmid-like minicircles, mostly containing one or more genes, and with a conserved core. We show here that, in addition to the transcripts of similar sizes to individual genes that have been reported previously, there are larger transcripts beginning and ending close to the core region. These may give rise to the smaller transcripts by processing.

Archaeal MCM has separable processivity, substrate choice and helicase domains.

The mini-chromosome maintenance (MCM) complex is the principal candidate for the replicative helicase of archaea and eukaryotes. Here, we describe a functional dissection of the roles of the three principal structural modules of the homomultimeric MCM of the hyperthermophilic archaeon Sulfolobus solfataricus. Our results include the first analysis of the central AAA+ domain in isolation.

DNA replication in the archaea.

The archaeal DNA replication machinery bears striking similarity to that of eukaryotes and is clearly distinct from the bacterial apparatus. In recent years, considerable advances have been made in understanding the biochemistry of the archaeal replication proteins. Furthermore, a number of structures have now been obtained for individual components and higher-order assemblies of archaeal replication factors, yielding important insights into the mechanisms of DNA replication in both archaea and eukaryotes.

GINS, a central nexus in the archaeal DNA replication fork.

In eukaryotes, the GINS complex is essential for DNA replication and has been implicated as having a role at the replication fork. This complex consists of four paralogous GINS subunits, Psf1, Psf2, Psf3 and Sld5. Here, we identify an archaeal GINS homologue as a direct interaction partner of the MCM helicase.