Final answer:
Group I self-splicing introns can act as ribozymes and convert into catalytic RNA molecules that facilitate splicing in trans. They use a guanine nucleotide cofactor to splice themselves out accurately, creating a mature mRNA necessary for protein synthesis.
Step-by-step explanation:
Group I self-splicing introns are unique in their ability to excise themselves from an RNA molecule without the need for proteins or small nuclear ribonucleoproteins (snRNPs). These introns can act as ribozymes, catalyzing their own removal. When acting in trans, Group I introns can convert into catalytic RNA molecules that facilitate the splicing of other RNA molecules, effectively behaving like enzymes. The removal of Group I introns occurs through a distinctive mechanism that involves a guanine nucleotide cofactor and results in the joining of the exons once the intron is spliced out. This process ensures the accurate synthesis of translatable mRNA, which is critical for the production of functional proteins.