PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of jbacterPermissionsJournals.ASM.orgJournalJB ArticleJournal InfoAuthorsReviewers
 
J Bacteriol. 1994 February; 176(3): 804–814.
PMCID: PMC205118

Genetic and molecular characterization of the Escherichia coli secD operon and its products.

Abstract

The secD operon of Escherichia coli is required for the efficient export of proteins. We have characterized this operon, and found that, in addition to secD and secF, it contains the upstream gene yajC, but not the genes queA or tgt, in contrast to previous reports. An analysis of yajC mutations constructed in vitro and recombined onto the chromosome indicates that yajC is neither essential nor a sec gene. The secD operon is not induced in response to either secretion defects or temperature changes. TnphoA fusions have been used to analyze the topology of SecD in the inner membrane; the protein contains six transmembrane stretches and a large periplasmic domain. TnphoA fusions to SecD and SecF have also been recombined onto the chromosome and used to determine the level of these proteins within the cell. Our results indicate that there are fewer than 30 SecD and SecF molecules per cell.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (2.3M), or click on a page image below to browse page by page.

Images in this article

Click on the image to see a larger version.

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)