Beta-barrel proteins from bacterial outer membranes: structure, function and refolding.

Recently solved outer membrane protein structures include the smallest and largest known beta-barrel structures, with functions distinct from the general and specific porins. Both protein expressed in outer membranes and protein deposited as cytoplasmic aggregates have been used for the structure determinations. As most beta-barrel proteins can be overexpressed in an aggregated form (inclusion bodies) and refolded to the native state, this provides an alternative to membrane-targeted expression strategies and yields sufficient quantities of protein for future structural studies.