A specialized histone associated with the centromeric region of the chromosome is:
A specialized histone associated with the centromeric region of the chromosome is:
Select an option to attempt
Correct Answer: Option A
Explanation
CenH3: centromere-specific histone variant:CenH3 (also called CENP-A in humans, CID in Drosophila) is a specialized histone H3 variant with a unique N-terminal tail and distinct CATD (CENP-A Targeting Domain) in the histone fold domain.Functions:• Specifically deposited at centromeric chromatin (replacing canonical H3).• Forms a centromeric nucleosome that serves as the epigenetic mark defining the centromere.• Recruits other CCAN (Constitutive Centromere-Associated Network) proteins.• Provides the platform for kinetochore assembly, which connects chromosomes to spindle microtubules during mitosis.Key: The location of centromeres is specified EPIGENETICALLY by CenH3, not by a specific DNA sequence in most organisms.Answer: CenH3 (CENP-A) is deposited at centromeric regions to define the kinetochore assembly platform.