About: Replisome is a research topic. Over the lifetime, 1509 publications have been published within this topic receiving 72080 citations. The topic is also known as: GO:0030894 & Replisome.
TL;DR: Structural and biochemical studies are starting to provide a first glimpse of how both PCNA temporally and spatially organise their functions and how both tasks can be achieved.
Abstract: Proliferating cell nuclear antigen (PCNA) was originally characterised as a DNA sliding clamp for replicative DNA polymerases and as an essential component of the eukaryotic chromosomal DNA replisome. Subsequent studies, however, have revealed its striking ability to interact with multiple partners, which are involved in several metabolic pathways, including Okazaki fragment processing, DNA repair, translesion DNA synthesis, DNA methylation, chromatin remodeling and cell cycle regulation. PCNA in mammalian cells thus appears to play a key role in controlling several reactions through the coordination and organisation of different partners. Two major questions have emerged: how do these proteins access PCNA in a coordinated manner, and how does PCNA temporally and spatially organise their functions? Structural and biochemical studies are starting to provide a first glimpse of how both tasks can be achieved.
TL;DR: Extensive biochemical and structural studies have provided detailed models of how TOP2 alters DNA structure, and recent molecular studies have greatly expanded knowledge of the biological contexts in which TOP2 functions, such as DNA replication, transcription and chromosome segregation.
Abstract: DNA topoisomerases are enzymes that disentangle the topological problems that arise in double-stranded DNA. Many of these can be solved by the generation of either single or double strand breaks. However, where there is a clear requirement to alter DNA topology by introducing transient double strand breaks, only DNA topoisomerase II (TOP2) can carry out this reaction. Extensive biochemical and structural studies have provided detailed models of how TOP2 alters DNA structure, and recent molecular studies have greatly expanded knowledge of the biological contexts in which TOP2 functions, such as DNA replication, transcription and chromosome segregation -- processes that are essential for preventing tumorigenesis.
TL;DR: The GINS (go ichi ni san) complex allows the MCM (minichromosome maintenance) helicase to interact with key regulatory proteins in large replisome progression complexes (RPCs) that are assembled during initiation and disassembled at the end of S phase.
Abstract: GINS maintains association of Cdc45 with MCM in replisome progression complexes at eukaryotic DNA replication forks
TL;DR: It is concluded that DNA gyrase controls the supercoiling of DNA in E. coli.
Abstract: Novobiocin and coumermycin are known to inhibit the replication of DNA iing of DNA catalyzed by E. coli DNA gyrase, a recently discovered enzyme that introduces negative superhelical turns into covalently circular DNA. The activity of DNA gyrase purified from a coumermycin-resistant mutant strain is resistant to both drugs. The inhibition by novobiocin of colicin E1 plasmid DNA replication in a cell-free system is partially relieved by adding resistant DNA gyrase. Both in the case of coliclls. DNA molecules which are converted to the covalently circular form in thepresence of coumermycin remain relaxed, instead of achieving their normal supercoiled conformation. We conclude that DNA gyrase controls the supercoiling of DNA in E. coli.
TL;DR: A heteropentameric AAA+ clamp-loading machine that couples ATP hydrolysis to load circular clamp proteins onto DNA and twin polymerases and clamps coordinate their actions to form a replisome machine that advances the replication fork.
Abstract: ▪ Abstract Chromosomal DNA replicases are multicomponent machines that have evolved clever strategies to perform their function. Although the structure of DNA is elegant in its simplicity, the job of duplicating it is far from simple. At the heart of the replicase machinery is a heteropentameric AAA+ clamp-loading machine that couples ATP hydrolysis to load circular clamp proteins onto DNA. The clamps encircle DNA and hold polymerases to the template for processive action. Clamp-loader and sliding clamp structures have been solved in both prokaryotic and eukaryotic systems. The heteropentameric clamp loaders are circular oligomers, reflecting the circular shape of their respective clamp substrates. Clamps and clamp loaders also function in other DNA metabolic processes, including repair, checkpoint mechanisms, and cell cycle progression. Twin polymerases and clamps coordinate their actions with a clamp loader and yet other proteins to form a replisome machine that advances the replication fork.