#Question id: 2891
#Unit 2. Cellular Organization
Which of the following statements regarding the Structural Maintenance Chromosomal proteins is correct?
A. The cohesins, along with a third protein, kleisin, are thought to form a ring around the replicated chromosomes.
B. Condensin binding causes the DNA to become underwound, in contrast to the overwinding induced by the binding of nucleosomes.
C. Cohesins are made up of pairs of Smc1 and Smc3 proteins, and condensins consist of Smc2-Smc4 pairs.
D. The primary structure of SMC proteins consists of three distinct domains.
#Question id: 2892
#Unit 2. Cellular Organization
The edges of each base pair are exposed in the major and minor grooves, creating a pattern of hydrogen-bond donors and acceptors and of hydrophobic groups (allowing for Vander Waals interactions) that identifies the base pair. The edge of an T : A base pair displays the following chemical groups in the following order in the major groove:
#Question id: 2893
#Unit 2. Cellular Organization
Which of the following statement regarding the Nucleosome-remodeling complexes is CORRECT?
#Question id: 2894
#Unit 2. Cellular Organization
Which of the following statements is INCORRECT regarding the assembly of DNA into higher-order chromatin structure?
I. Histone H1 is not part of the histone octamer, but binds to linker DNA and is responsible for higher-order chromatin structure.
II. The 30 nm fibers of a chromosome are attached to a/an RNA-protein scaffold that holds the fibers in large loops.
III. It is not possible for linear DNA to be supercoiled. Only circular DNA, which has no ends, can have regions of supercoiling.
IV. Core histones lacking their amino-terminal tails are capable of forming 30-nm fibers as they help to stabilize the 30-nm fiber in internucleosomal interactions.
#Question id: 2895
#Unit 2. Cellular Organization
Match the following histone modifying enzymes with the respective functions they catalyze.
COLUMN I COLUMN II
1. NuRD, SIR2 complex a. Histone Acetyltransferase Complexes
2. LSD1, JHMD3 b. Histone Deacetylase Complexes
3. SUV39, DOT1 c. Histone Demethylases
4. P300/CBP, PCAF d. Histone Methyltransferases
#Question id: 2896
#Unit 2. Cellular Organization
Different modification states of the residue Lys-9 on the tail of histone H3 could be interpreted to have different meanings. One example of how a histone modification can apparently influence a second modification present nearby is illustrated by the Drosophila HP1 protein. Which of the following statement is correct regarding this kind of epigenetic regulation?