Final answer:
The 3' end formation of histone mRNA requires U7 snRNA, which binds to the 3' end and helps in mRNA processing and stabilization. An internally complementary sequence near the 3' end forms a hairpin loop structure that serves as a termination signal. Other factors like RNA-binding proteins and poly(A) polymerase are also involved.
Step-by-step explanation:
The 3' end formation of histone mRNA requires U7 snRNA. U7 snRNA is a small nuclear RNA that binds to the 3' end of histone mRNA and helps in the processing and stabilization of the mRNA molecule.
During the formation of histone mRNA, an internally complementary sequence near the 3' end of the transcript folds to form a secondary hairpin loop structure. This hairpin loop structure serves as a termination signal and helps in the cleavage and polyadenylation of the mRNA. U7 snRNA binds to this hairpin structure and recruits proteins necessary for mRNA processing.
In addition to U7 snRNA, other factors such as RNA-binding proteins and poly(A) polymerase are involved in the 3' end formation of histone mRNA. These factors recognize specific sequences or structures near the 3' end of histone mRNA and play important roles in mRNA processing and stability.