Native β-barrel substrates pass through two shared intermediates during folding on the BAM complex.

ABSTRACT: The assembly of β-barrel proteins into membranes is mediated by the evolutionarily conserved β-barrel assembly machine (BAM) complex. In Escherichia coli, BAM folds numerous substrates which vary considerably in size and shape. How BAM is able to efficiently fold such a diverse array of β-barrel substrates is not clear. Here, we develop a disulfide crosslinking method to trap native substrates in vivo as they fold on BAM. By placing a cysteine within the luminal wall of the BamA barrel as well as in the substrate β-strands, we can compare the residence time of each substrate strand within the BamA lumen. We validated this method using two defective, slow-folding substrates. We used this method to characterize stable intermediates which occur during folding of two structurally differ

SUBMITTER: Dos Santos TMA 

PROVIDER: S-EPMC11494362 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature