Hydrophobic forces drive spontaneous membrane insertion of the bacteriophage Pf3 coat protein without topological control.

Authors

D Kiefer
A Kuhn

Publication/Presentation Date

11-15-1999

Abstract

Bacterial integral inner membrane proteins are either translocated across the lipid bilayer using an energy-driven enzyme, such as the Sec translocase, or they might interact directly with the membrane due to hydrophobic forces. We report that the single-spanning Pf3 coat protein is spontaneously inserted into the membrane of Escherichia coli and requires the electrical component of the membrane potential (DeltaPsi) to translocate its N-terminal region. This results in a final N(out)C(in) orientation of the protein in the cytoplasmic membrane, due the potential-driven translocation of the aspartyl residue at position 18 in the hydrophilic N-terminal tail. Uncharged protein tails are only translocated when the hydrophobic transmembrane region of the protein has been extended. An extended transmembrane anchor allows membrane insertion in the absence of an electrochemical membrane potential, but also causes the loss of a strict determination of the topology.

Volume

18

Issue

22

First Page

6299

Last Page

6306

ISSN

0261-4189

Disciplines

Medicine and Health Sciences

PubMedID

10562542

Department(s)

Department of Obstetrics and Gynecology

Document Type

Article

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