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Flashcards in Chromosome Structure Deck (17):
1

What do errors in the centromere cause

Aberrant division
Chromosome instability

2

What is the centromere made up of

Repetitive satellite DNA making up 3 sub domains: CDE 1, 2, 3 and up to 20 different proteins

3

What types of DNA make up the centromere

Alpha DNA
Satellite 1, 2, 3

4

What's so special about alpha DNA in the centromere

It's a 171bp repeat, each of which is the binding site for CENP-B

5

What are the two types of proteins associated with the centromere

1) CENP-A, B, C: proteins constitutively associated with the centromere.
2) passenger proteins: proteins that are transiently associated during different phase of the cell cycle

6

Give an example of a passenger protein

ESCO2
SMC3

7

What group of disease are associated with passenger proteins of the centromere

Cohesinopathies
ESCO2: Roberts syndrome
SMC3: Cornelia de Lange

8

What's a kinetochore

Large multiple protein (80) plate like structure
That assemble either side of the centromere and acts as a pint of attachment for spindle fibers

9

What's a telomere

Highly conserved gene poor chromosome cap

10

What's the role of the telomere

Maintain structural integrity (prevent sticky ends).
A role in the 3D architecture of the cell (positioning of chromosomes in the nucleus)

11

What's the structure of the telomere

TTAGGG tandem repeats (3-20kb).
TAR (telomere associated repeats) (100-330kb).
Subtelomer (unique sequence)

12

What telomerase

Carries a TAGG antisense template to prime DNA synthesis on the leading strand to extend the telomere. This provides a template for the DNA polymerase to bind to to complete synthesis of the lagging strand

13

What NOR Stand for

Nucleolar organising region

14

Where is are the NOR

Stalks of the acrocentric: p12

15

What DNA do the NORs consist of

Satellite DNA 1, 2, 3, alpha and beta

16

What rRNA are on the NORs

28S, 5.8S, 18S.
In 13kb tandem repeats 50-60 times

17

What is the centromere

Highly specialised.
Foundation for kinetochore assembly.
Site for sister chromatid attachment.
Required for accurate. Chromosome segregation