Work

The Bacterial ATPase SecA Functions as a Monomer in Protein Translocation

Year: 2004

Type: article

Abstract: The ATPase SecA drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. To address the functional importance of the monomeric state, we generated an Escherichia coli SecA mutant that is almost completely monomeric (>99%), consistent with predictions from the crystal structure of Bacillus subtilis SecA. In vitro, the monomeric derivative retained significant activity in various assays, and in vivo, it sustained 85% of the growth rate of wild type cells and reduced the accumulation of precursor proteins in the cytoplasm. Disulfide cross-linking in intact cells showed that mutant SecA is monomeric and that even its parental dimeric form is dissociated. Our results suggest that SecA functions as a monomer during protein translocation in vivo.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.m413947200

Authors: Eran Or, Dana Boyd, Stéphanie Gon, Jonathan Beckwith, Tom Rapoport

Institutions: Howard Hughes Medical Institute, Harvard University, Baim Institute for Clinical Research

Language: English

Topic: Bacterial Genetics and Biotechnology

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: National Cancer Institute, National Institute of General Medical Sciences