Final answer:
The peptide GFGILAVI is likely part of a single-pass transmembrane protein in the ER due to its hydrophobic amino acids, which suggest a stop-transfer sequence common in integral membrane proteins.
Step-by-step explanation:
Protein Targeting Based on Amino Acid Sequence
The peptide sequence GFGILAVI, based on the nature of its amino acids, indicates the likelihood of being a part of a membrane-spanning protein. This conclusion is derived from the presence of hydrophobic amino acids that often comprise the stop-transfer sequence within membrane proteins.
These type of sequences are part of the integral membrane proteins that are embedded in the lipid bilayer. The hydrophobic property of the sequence allows the peptide to be retained within the membrane, suggesting that it is likely to be a single-pass transmembrane protein. Given the probable localization and function, the peptide's sequence does not possess the typical signals for peroxisomal, nuclear, or chloroplast targeting.
When analyzing the sequence for potential protein folding, modification, and targeting, it is important to consider the hydrophobic properties and how these would interact with the cell's endomembrane system, such as the rough endoplasmic reticulum (RER) where initial protein synthesis takes place before post-translational modifications occur.
Therefore, the correct answer is E) A protein that is most likely a single-pass transmembrane protein in the ER.