Integrins are single-pass integral membrane proteins in the plasma membrane of animal cells and are involved in the interaction of the cell with the surrounding extracellular matrix. Which of the following descriptions do you think matches the transmembrane part of an integrin molecule?
A) It forms a β barrel.
B) It is an α helix that is bent in the middle.
C) It is about 10 amino acids long, with every other amino acid side chain being hydrophobic.
D) It folds in a conformation with maximal intrachain hydrogen-bonding.
E) It is about 100 amino acids long.

Question

Quizplus · Accepted Answer

Folding of a transmembrane segment into an α -helical conformation maximizes hydrogen-bonding in the absence of water. The hydrogen-bonding requirement is also satisfied in the multipass β barrel structures.

Integrins Are Single-Pass Integral Membrane Proteins in the Plasma Membrane