C-terminal kink formation is required for lateral gating in BamA

Abstract

Significance Nearly all outer-membrane proteins (OMPs) in Gram-negative bacteria are inserted via the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>β</mml:mi> </mml:math> -barrel assembly machinery (BAM) complex. Molecular dynamics simulations have revealed a persistent C-terminal strand kink of the core BAM component, BamA, which permits BamA to open laterally to the membrane. Experiments show that inhibiting kinking makes bacteria more susceptible to antibiotics. Kink-induced lateral gating may catalyze OMP insertion through a local disruption of the membrane, a pathway into the membrane, or both.