DNA Packaging&Organization
Result of homology-directed repair of a double-stranded DNA break
Gene conversion
T/F: Histone H1 is part of the nucleosome core particle
False: Histone H1 is a linker histone
Components that form the histone fold structural motif
3 a-helices connected by 2 loops
Histones H2A, H2B, H3, and H4 form a histone octamer around which DNA wraps about ___ base pairs
147
Amount of methyl groups that can be added to lysine
3
When sister chromatids are unavailable, ___ can serve as templates for HDR
homologous chromosomes
In regards to chromatin-associated species, the statement that readers are recognition enzymes that bind specific histone marks is___
False.
Erasers
HDM and HDAC
The basic repeating unit of chromatin
nucleosome
Amount of methyl groups that can be added to Arginine
2
Model that describes chromatin fiber compaction
Zigzag model
HDR can use homologous chromosomes as templates in G1
True
Class of nuclear eukaryotic DNA that is localized to centromeric heterochromatin
Simple-sequence satellite DNA
How many turns of DNA are wrapped around each nucleosome?
1.7
Barrier DNA-protein complexes
Block the spread of reader-writer complexes and separate neighboring chromatin domains
DNA sequences that bind most tightly to nucleosomes
AA, TT, TA
Fanconi anemia is caused by mutations in FANC genes, leading to increased DNA repair efficiency
False. Fanconi anemia is caused by defects in FANC genes and induces bone marrow failure& predisposition to cancer
Order of events that initiate HDR of DSBs
1. Strand invasion
2. D-loop formation
3. DNA synthesis
Can be slid, removed, or replaced by ATP-dependent chromatin-remodeling complexes
nucleosomes
Chromatin-modifying enzymes such as kinases, HMTs, and HATs
Writers
Stabilizes replication forks blocked by ICLs
FANCM and core FA complex
Replication forks that have stalled due to DNA damage can be rescued by BER or NER mechanisms
True. BER or NER pathways can repair lesion that caused fork to stall.
Section of chromatin containing 868 DNA bps and 4 histone octamers is treated with nuclease. How much DNA (in bp) would be digested?
280
Chromatin-remodeling complex that replaces H2A-H2B dimers with histone variants
SWR1
Proteins involved in HDR of ICLs
RPA/ATR, FANCM, ubiquitin, translesion polymerase