Membrane protein assembly: rules of the game.

Integral membrane proteins are found in all cellular membranes and fulfil many of the functions that are central to life. A critical step in the biosynthesis of membrane proteins is their insertion into the lipid bilayer. The mechanisms of membrane protein insertion and folding are becoming increasingly better understood, and efficient methods for the ab initio prediction of three-dimensional protein structure from the primary amino acid sequence may be within reach. Already, the basic tools needed for engineering and de novo design of integral membrane proteins seem to be at hand.