Figure 14.26. Non-homologous end-joining (NHEJ) in humans.

Figure 14.26Non-homologous end-joining (NHEJ) in humans

(A) The repair process. Additional proteins not shown in the diagram are also involved in NHEJ. These include the protein kinases ATM and ATR (Section 13.3.2), whose main role may be to signal to the cell the fact that a double-strand break has occurred and the cell cycle should be arrested until the break is repaired. If the cell enters mitosis with a broken chromosome then part of that chromosome will be lost, because only one of the fragments will contain a centromere, and centromeres are essential for distribution of chromosomes to the daughter nuclei during anaphase (see Figure 5.14). (B) Structure of the Ku-DNA complex. On the left is the view looking down onto the broken end of the DNA double helix, and on the right is the side view, with the broken end of the DNA molecule on the left. Ku is a heterodimer made up of the Ku70 and Ku80 subunits, the numbers indicating the molecular masses in kDa. Ku70 is colored red and Ku80 orange. The DNA molecule is shown in gray. Reprinted with permission from Walker et al., Nature, 412, 607–614. Copyright Macmilllan Magazines Limited.

Image ch5f14

From: Chapter 14, Mutation, Repair and Recombination

Cover of Genomes
Genomes. 2nd edition.
Brown TA.
Oxford: Wiley-Liss; 2002.
Copyright © 2002, Garland Science.

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