Final answer:
The consensus sequence for the 3' splice site is typically 'YAG', where Y is a pyrimidine nucleotide and AG is the invariant dinucleotide marking the intron's end.
Step-by-step explanation:
The consensus sequence for the 3' splice site marks the region where intronic sequences are removed during mRNA processing. This sequence signals where splicing machinery should make a cut to splice out an intron.
A typical 3' splice site is recognized by the sequence 'YAG' where Y indicates a pyrimidine nucleotide, and AG is the invariant dinucleotide that delineates the end of the intron. Following this, downstream nucleotides that are toward the 3' end relative to a site on the mRNA will be joined with the exons to form the mature mRNA transcript.
In the context of RNA splicing, a hairpin loop structure might refer to a termination signal in prokaryotes or to a lariat structure formed during splicing in eukaryotes. However, this structure is not directly related to the 3' splice site which is at the end of an intron. Key elements for functional splice sites are often determined through consensus sequences gathered from a large dataset of known splicing events.
It's also important to note the role of other consensus sequences in mRNA processing, such as the Kozak consensus sequence which is critical for the initiation of translation. Similarly, consensus sequences can define codons, which are the basic unit of genetic code and specify which amino acid will be added to a growing polypeptide chain.