Back

Membrane voltage-dependent activation of the flagellar protein export engine

Minamino, T.; Morimoto, Y. V.; Kinoshita, M.; Namba, K.

2020-07-18 microbiology
10.1101/2020.07.18.210377 bioRxiv
Show abstract

Ion motive force (IMF) consists of the electric potential difference ({Delta}{Psi}) and the ion concentration difference ({Delta}pI) across the cytoplasmic membrane. The flagellar protein export machinery is an ion/protein antiporter utilizing IMF to drive ion-coupled protein export, but it remains unknown how. Here, we report a {Delta}{Psi}-dependent activation mechanism of the transmembrane export gate complex. Depletions of both H+ and Na+ gradients nearly diminished flagellar protein export in the absence of the cytoplasmic ATPase complex, but an increase in {Delta}{Psi} by an upward shift of external pH from 7.5 to 8.5 dramatically recovered it. An increase in the cytoplasmic level of export substrates and gain-of-function mutations in FlhA enhanced protein export at external pH 7.5 in the absence of Na+ in a similar manner to {Delta}{Psi} increase. We propose that the export gate complex has a voltage-gated mechanism to activate the ion/protein antiporter of the flagellar protein export engine.

Matching journals

The top 5 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.