Final answer:
Cse4p is the histone variant present in the yeast centromere, functionally analogous to the human CENP-A. It plays a crucial role in centromere structure and chromosome segregation during cell division.
Step-by-step explanation:
The histone variant present in the yeast centromere is known as the Cse4p. It is analogous to the CENP-A found in humans and is crucial for the structure and function of centromeres during cell division. In contrast to the canonical histone H3, Cse4p contains a unique N-terminal tail that aids in the distinctive centromeric chromatin structure.
During cell division, particularly in mitosis and meiosis, proper chromosome segregation is dependent on the centromere and its associated proteins, which include the histone variant Cse4p. This variant plays a key role in the formation of the kinetochore, a protein complex that is essential for the attachment of chromosomes to the mitotic spindle and their accurate segregation.
Among the options provided (CENP-A, Ctf19, Mcm21), Cse4p is the specialized histone variant related to histone H3 that is found in the yeast centromere, fulfilling a similar role to CENP-A in higher eukaryotes.