Question

The introductory passage mentions that halomucin was predicted to contain a signal sequence and that later research found evidence of the protein outside of the H. walsbyi cell. What is the best description of a signal sequence?

Choose the best answer.

Hints

Choose the best answer.

A) A signal sequence is 15-20 residues of a protein that has a central hydrophobic region and polar ends. It facilitates folding in order to make transport across the membrane easier.

B) A signal sequence is 15-20 residues of a protein that has a central hydrophilic region and nonpolar ends. It is found only in bacteria, in which it marks a protein for export by the translocase system.

C) A signal sequence is 15-20 residues of a protein that has a central hydrophobic region and polar ends. It hampers folding, which could prevent efficient secretion, and marks the protein for export by the translocase system.

D) A signal sequence is 15-20 residues at the N terminus of a protein. It is found only in archaea, in which it marks a protein for export by the translocase system.

E) A signal sequence if 15-20 residues at the C terminus of a protein. It is found in archaeans and in bacteria and marks proteins for export by the translocase system.