Mechanisms of MCM2-7 loading and initial DNA melting at near base-pair resolution
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1003856 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR25592629.fastq.gz | Fastqsanger.gz | |||
| SRR25592630.fastq.gz | Fastqsanger.gz | |||
| SRR25592631.fastq.gz | Fastqsanger.gz | |||
| SRR25592632.fastq.gz | Fastqsanger.gz | |||
| SRR25592633.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 36 |
Similar Datasets
Project description:The loading and activation of the replicative helicase MCM2-7 are key events during the G1-S phase transition.In budding yeast, the origin recognition complex (ORC) binds to the conserved DNA elements A and B1 of the autonomously replicating sequence (ARS).This is followed by the consecutive loading of two MCM2-7 hetero-hexamers into a MCM2-7 double-hexamer(DH).In S-phase the MCM2-7DH is activated, resulting in two Cdc45-MCM-GINS(CMG) helicases that bidirectionally unwind DNA ahead of the replication fork.Here,we show that MCM2-7 helicase loading across the B1 element displaces ORC fromo rigins.This allows ORC binding and helicase loading at lower affinity binding sites and origins throughout the genome.Furthermore, we mapped the sites of initial DNA unwinding genome-wide and show that these sites appear near the N-terminal domains of the MCM2-7 double-hexamer in proximity of the B1 element.Finally, employing a chemical-biology approach, we establish that during helicase activation the Mcm2/5 interface acts as the DNA exit gate for single-stranded-DNA extrusion.Our work identifies that helicase loading follows a distributive mechanism, allowing for equal MCM2-7 loading across the genome and surprisingly finds that DNA unwinding initiates from the helicase N-terminal interface in proximity to the ARS B1 element.
2024-06-21 | GSE240472 | GEO
Project description:The loading and activation of the replicative helicase MCM2-7 are key events during the G1-S phase transition. In budding yeast, the origin recognition complex (ORC) binds to the conserved DNA elements A and B1 of the autonomously replicating sequence (ARS). This is followed by the consecutive loading of two MCM2-7 hetero-hexamers into a MCM2-7 double-hexamer (DH). In S-phase the MCM2-7 DH is activated, resulting in two Cdc45-MCM-GINS (CMG) helicases that bidirectionally unwind DNA ahead of the replication fork. Here, we show that MCM2-7 helicase loading across the B1 element displaces ORC from origins. This allows ORC binding and helicase loading at lower affinity binding sites and origins throughout the genome. Furthermore, we mapped the sites of initial DNA unwinding genome-wide and show that these sites appear near the N-terminal domains of the MCM2-7 double-hexamer in proximity of the B1 element. Finally, employing a chemical-biology approach, we establish that during helicase activation the Mcm2/5 interface acts as the DNA exit gate for single-stranded-DNA extrusion. Our work identifies that helicase loading follows a distributive mechanism, allowing for equal MCM2-7 loading across the genome and surprisingly finds that DNA unwinding initiates from the helicase N-terminal interface in proximity to the ARS B1 element.
2024-06-21 | GSE173527 | GEO
Project description:Mechanisms of MCM2-7 loading and initial DNA melting at near base-pair resolution [MCM4 & ORC2 ChIP-exo]
| PRJNA725895 | ENA
Project description:We employ ChIP-seq methodology to study genome-wide distribution of MCM2, NIPBL and cohesin in thymidine-arrested cells
2018-04-10 | GSE112028 | GEO
Project description:The origin recognition complex (ORC) nucleates DNA replication initiation in eukaryotic cells. This six-protein complex binds replication origin DNA, recruits other initiation factors and facilitates loading of the DNA helicase. Studying the function of individual ORC subunits during pre-RC formation has been hampered by the requirement of most subunits for DNA binding. In this study, we investigate the function of the S. cerevisiae Orc6 subunit, the only subunit not required for DNA binding. In vivo, depletion of Orc6 inhibits pre-replicative complex (pre-RC) assembly and maintenance. In vitro, ORC lacking Orc6 fails to interact with Cdt1 and to load the Mcm2-7 helicase onto origin DNA. We demonstrate that two regions of Orc6 bind Cdt1 directly and that the extreme C-terminus of Orc6 (Orc6-CTD) interacts tightly with the remaining five ORC subunits. Replacing Orc6 with a fusion protein linking Cdt1 to the Orc6-CTD results in an ORC complex that loads Mcm2-7 onto DNA. Interestingly, this complex can only perform a single round of Mcm2-7 loading, suggesting that a dynamic association of Cdt1 with ORC is required for multiple rounds of pre-RC assembly. Keywords: ChIP-chip
2007-11-14 | GSE9318 | GEO
Project description:Determination of the genome-wide distribution of the Mcm2-7 helicase by chromatin immunoprecipitation in the Drosophila Kc167 cell line at the beginning of S phase. Kc167 cells were arrested at the G1/S transition with hydroxyurea (HU). Goal was to evaluate changes in the genome-wide Mcm2-7 distribution throughout the cell cycle, and how this relates to the excess Mcm2-7 loaded onto chromatin in G1. ChIP-Chip of Mcm2-7 in HU compared to input genomic DNA. Biological Replicates: 2
2014-11-27 | E-GEOD-63680 | biostudies-arrayexpress
Project description:In eukaryotes, DNA replication initiation requires assembly and activation of the minichromosome maintenance (MCM) 2-7 double hexamer (DH) to melt origin DNA strands. However, the mechanism for this initial melting is unknown. Here, we report a 2.59-Å cryo-electron microscopy structure of the endogenously purified human MCM-DH (hMCM-DH), also known as the pre-replication complex. In this structure, the hMCM-DH shows a constricted central channel with a diameter of only 13 Å at the hexamer interface. This unusual conformation untwists and stretches the DNA strands such that almost a half turn of the bound duplex DNA is distorted with one-base pair completely separated, generating an initial open structure (IOS) at the hexamer junction. This IOS is captured and stabilized by zinc fingers (ZFs) of MCM2 and MCM5 from opposing hexamers. Disturbing the interaction between MCM5-ZF and the IOS demonstrably inhibits DH formation and replication initiation. High-resolution mapping of hMCM-DH footprints indicates that IOSs are distributed across the human genome in large clusters aligning perfectly with initiation zones to safeguard robust stochastic origin firing. This work unravels an intrinsic mechanism that couples DH formation with initial DNA melting to license replication initiation in human cells.
2022-12-31 | GSE202066 | GEO
Project description:Determination of the genome-wide distribution of the Mcm2-7 helicase by chromatin immunoprecipitation in the Drosophila Kc167 cell line at the beginning of S phase. Kc167 cells were arrested at the G1/S transition with hydroxyurea (HU). Goal was to evaluate changes in the genome-wide Mcm2-7 distribution throughout the cell cycle, and how this relates to the excess Mcm2-7 loaded onto chromatin in G1.
2014-11-27 | GSE63680 | GEO
Project description:Chromatin immunoprecipitation of the MCM2-7 replicative helicase followed by hybridization to genome-wide tiling microarrays demonstrated that MCMs localize to the follicle cell amplicons at stages of replication initiation Comparison of MCM2-7 ChIP sample compared to input DNA for Drosophila egg chambers
2011-09-06 | E-GEOD-31889 | biostudies-arrayexpress
Project description:Mcm2, a subunit of the Mcm2-7 helicase best known for its role in DNA replication, contains a histone binding motif that facilitates the transfer of parental histone following DNA replication. Here we show that Mcm2 is important for the differentiation of mouse embryonic stem (ES) cells. Mcm2-2A mutation defective in histone binding impairs differentiation and programmatic changes in gene expression and histone modifications during differentiation. Mcm2 localizes at the transcription starting sites and the binding of Mcm2 at gene promoters is disrupted in both Mcm2-2A ES cells and neuro-precursor cells (NPCs). Reduced Mcm2 binding in Mcm2-2A ES cells correlates with decreased chromatin accessibility at bivalent chromatin domains containing repressive H3K27me3 and active H3K4me3 modifications in NPCs. Together, our studies reveal a novel function of Mcm2 in ES differentiation, likely through manipulating chromatin landscape at bivalent chromatin domains.
2022-11-16 | GSE203271 | GEO