Watching helical membrane proteins fold reveals a common N-to-C-terminal folding pathway
A pathway for helical membrane proteins Membrane proteins are inserted into cell membranes while they are being translated and may fold concurrently into their secondary and tertiary structures. Choi et al. describe a single-molecule force microscopy technique that allowed them to monitor folding of helical membrane proteins in vesicles and bicelles. Two helical membrane proteins, the Escherichia coli rhomboid protease GlpG and the human β 2 -adrenergic receptor, both folded from the N to the C terminus, with structures forming in units of helical hairpins. In the cell, this would allow these proteins to begin folding while being translated. Science , this issue p. 1150