Which components form the spliceosome?

Which components form the spliceosome?

• A. snRNPs and proteins.
• B. DNA polymerases.
• C. Ribosomes.
• D. Helicases.

Answer: (A)

Spliceosome function relies on a specific molecular machine built from small nuclear ribonucleoproteins, or snRNPs, plus a complement of associated proteins. The snRNPs are complexes that combine small nuclear RNA with proteins, and together the major snRNPs—U1, U2, U4, U5, and U6—assemble with additional proteins to recognize the splice sites and branch point in pre-mRNA. This assembly drives the two catalytic steps that remove introns and join the exons. The proteins support the snRNPs by stabilizing structure, coordinating assembly and rearrangements, and enabling catalysis. In contrast, DNA polymerases are involved in DNA replication, ribosomes perform protein synthesis, and helicases unwind nucleic acids and assist remodeling but do not form the core spliceosome as snRNPs and proteins do.

Spliceosome function relies on a specific molecular machine built from small nuclear ribonucleoproteins, or snRNPs, plus a complement of associated proteins. The snRNPs are complexes that combine small nuclear RNA with proteins, and together the major snRNPs—U1, U2, U4, U5, and U6—assemble with additional proteins to recognize the splice sites and branch point in pre-mRNA. This assembly drives the two catalytic steps that remove introns and join the exons. The proteins support the snRNPs by stabilizing structure, coordinating assembly and rearrangements, and enabling catalysis. In contrast, DNA polymerases are involved in DNA replication, ribosomes perform protein synthesis, and helicases unwind nucleic acids and assist remodeling but do not form the core spliceosome as snRNPs and proteins do.