Role of the non-essential region encompassing the N-terminal two transmembrane stretches of Escherichia coli SecE.
SecE is an essential component of the protein translocation machinery of Escherichia coli and has three transmembrane stretches. An N-terminal region (SecE-N) encompassing the first two transmembrane stretches is dispensable for protein translocation but a SecE derivative (SecE-C) lacking this region is very unstable. We show here that FtsH, the AAA (ATPases associated with diverse cellular activities) family protease, causes the instability of SecE-C. SecE-C became stable when SecE-N was co-expressed. Deletion of the N-terminal region of SecE also rendered the SecE-SecY-SecG complex unstable. In spite of these alterations, the N-terminal region of SecE had little stimulatory effect on protein translocation in vivo or in vitro.
Nishiyama
K
K
Institute of Molecular and Cellular Biosciences, The University of Tokyo, Japan.
Suzuki
H
H
Tokuda
H
H
D001426:Bacterial Proteins / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D000069816:SEC Translocation Channels
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D000069816:SEC Translocation Channels; C065493:SecE protein, E coli