The ESR Raquel Rodríguez-Alonso just published a paper on how lipoprotein-β-barrel complexes are formed.
The crystal structure of the key BAM component BamA in complex with RcsF was reported.
BamA adopts an inward-open conformation, with the lateral gate to the membrane closed. RcsF is lodged deep within the lumen of the BamA barrel, binding regions proposed to undergo outward and lateral opening during OMP insertion.
On the basis of their structural and biochemical data, the authors proposed a push-and-pull model for RcsF export following conformational cycling of BamA, and provided a mechanistic explanation for how RcsF uses its interaction with BamA to detect envelope stress. Moreover, it was also suggested that the flux of incoming OMP substrates is involved in the control of BAM activity.
More info: https://www.nature.com/articles/s41589-020-0575-0