Chromosome structure Flashcards
- What happens with the N-terminal tails of these protein subunits? (histones)
They project outwards making them free to interact with regulating chromatin structure and function
- What do linker histones do?
Linker histones such as H1 attach DNA into histone octamers and limit DNA movement
- Name a linker histone and what form is chromatin in when it has linker histones?
H1 – Heterochromatin (silent chromatin)
- Transcriptionally inert
- Where are fractal globules found and what can they do?
Found in interphase chromatin and can reversibly condense and decondense without becoming tangled
- Where is transcriptionally active DNA found in interphase nuclei?
The periphery is where inactive heterochromatin is
- Where are alpha-satellite DNA repeats found on a chromosome
Centromeres
- Non-coding DNA
- Main component of centromeres and heterochromatin
- What are the 2 plates of the kinetochore called?
Inner plate and outer plate
- What does the alpha satellite DNA bind to?
Inner plate of the kinetochore
- What do the microtubules bind to?
The outer plate of the kinetochore
- What do lower order repeats bind to?
What kind of protein variant?
Histone variant centromeric protein A (CENP-A)
- What makes specific contact with the inner kinetochore plate?
CENP-A
- What does this form?
A nucleosome rich in CENP-A
- What are the 3 types of transposons
Retroviral
Retroviral like (retrotransposons)
DNA only transposons
- Mobile within genome
- How do DNA transposons move within DNA?
Via ‘cut & paste’ transposase cuts DNA out repairs cut and sticks it randomly elsewhere
- Why are DNA transposons so common?
The repairs can be shit and cause mutations and there can be shuffling of genes
- Important in gene evolution
