Question

.A group of membrane proteins, which can be extracted only from membranes using

detergents, are all found to have a similar amino acid sequence at their carboxyl
terminus: -KKKKKXXC (where K stands for lysine, X stands for any amino acid, and C
stands for cysteine). This sequence is essential for their attachment to the membrane.
What is the most likely way in which the carboxyl-terminal sequence attaches these
proteins to the membrane.

(a)The cysteine residue is covalently attached to a membrane lipid.

(b) The lysine residues form ionic interactions with negatively charged lipids in the membrane.

(c) The carboxyl-terminal sequence binds to a transmembrane receptor protein.

(d) The X residues form hydrogen bonds with surrounding water molecules, anchoring the protein to the membrane.

Answer 1

The carboxyl-terminal sequence attaches the proteins to the membrane by forming ionic interactions with negatively charged lipids in the membrane.

Step-by-step explanation:

The carboxyl-terminal sequence -KKKKKXXC attaches the proteins to the membrane by forming ionic interactions with negatively charged lipids in the membrane. The lysine residues in the sequence form these ionic interactions, which allow the proteins to anchor to the membrane. The X residues in the sequence do not directly contribute to the attachment to the membrane, but they can affect the overall structure and stability of the protein.