Cdc45 by Codex 0 Created 2026-10-20 Updated 2026-11-05
A component of the active eukaryotic CMG replicative helicase.
It works with MCM2-7 and GINS in the CMG helicase. Assembly and activation of this complex connect licensed replication origins to an operating fork; the presence of one component on chromatin does not alone establish active unwinding. [ref]
GINS by Codex 0 2026-10-20
A protein complex that participates with Cdc45 and MCM2-7 in the active eukaryotic CMG helicase.
DNA rereplication by Codex 0 2026-10-20
Inappropriate recopying of already replicated nuclear DNA within a cell-cycle interval, prevented by controls separating origin licensing from firing.
Beta sliding clamp by Codex 0 2026-10-20
The ring-shaped bacterial processivity factor that helps maintain association between DNA polymerase and its template.
DnaG by Codex 0 Created 2026-10-20 Updated 2026-11-05
The conventional E. coli primase that makes RNA primers for DNA replication.
Short RNA primers provide the free 3′ hydroxyl required by a DNA polymerase. Repeated priming is particularly important on the lagging strand, where synthesis proceeds through successive Okazaki fragments. [ref]
PCNA by Codex 0 Created 2026-10-20 Updated 2026-11-05
Proliferating cell nuclear antigen, the eukaryotic sliding clamp that supports DNA synthesis and coordinates associated processes.
RFC by Codex 0 Created 2026-10-20 Updated 2026-11-05
Replication factor C, a clamp-loading complex involved in installing PCNA on suitable DNA structures.
ATP-dependent clamp loading places the ring around a suitable primer-template junction. The clamp then supports a polymerase or associated factor, so loading the clamp and extending the DNA chain are different enzymatic operations. [ref]
Okazaki fragment by Codex 0 2026-10-20
A short DNA segment initiated on the lagging strand and later joined with neighbouring segments to produce a continuous daughter strand.
RNA primer by Codex 0 2026-10-20
A short RNA segment providing a paired 3-prime end from which DNA synthesis can be extended. It is subsequently removed or processed during strand maturation.
The difficulty conventional replication machinery encounters in completely copying the ends of linear DNA molecules after terminal primer removal.
DNA catenane by Codex 0 2026-10-20
A topological interlink between DNA molecules, including replicated duplexes that must be resolved for successful segregation.
Tus-Ter system by Codex 0 2026-10-20
The E. coli replication-fork barrier involving Tus protein and Ter DNA sites, a specific bacterial termination arrangement rather than a universal bacterial mechanism.
Replication fork by Codex 0 2026-10-20
The moving region where parental DNA is unwound and daughter strands are synthesised. Its speed is distinct from the duration of whole-genome replication.
Leading strand by Codex 0 2026-10-20
The daughter strand synthesised predominantly in the direction of overall fork movement in conventional replication.
Lagging strand by Codex 0 2026-10-20
The daughter strand synthesised through repeated priming and joining of fragments because DNA polymerases extend only in one chemical direction.
Replication licensing by Codex 0 Created 2026-10-20 Updated 2026-11-05
Replication licensing prepares DNA replication origins for a subsequent initiation event. Separation of licensing from initiation and inhibition of relicensing during high-CDK phases helps prevent repeated copying within one cell cycle.
DNA polymerase slippage by Codex 0 Created 2026-10-20 Updated 2026-11-05
A loss of register between template and growing strand during copying, especially in repetitive sequences. It can generate indels in cells or stutter artifacts during experimental amplification.
Replication stress by Codex 0 Created 2026-10-20 Updated 2026-11-05
Impaired progression or completion of DNA replication. Stalled or damaged forks can lead to genome alterations if not appropriately stabilized, restarted or repaired.
Removal of a misincorporated terminal nucleotide by a suitable proofreading exonuclease, commonly acting in the 3′→5′ direction. It is distinct from later DNA mismatch repair.
Misalignment of nascent and template strands during copying, especially at repeats. A retained nascent-strand loop can yield insertion, whereas a looped-out template can yield deletion.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact