Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Escherichia coli SecB Protein Associates with Exported Protein Precursors in vivo

Carol A. Kumamoto
Proceedings of the National Academy of Sciences of the United States of America
Vol. 86, No. 14 (Jul. 15, 1989), pp. 5320-5324
Stable URL: http://www.jstor.org/stable/34471
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Escherichia coli SecB Protein Associates with Exported Protein Precursors in vivo
Preview not available

Abstract

The product of the Escherichia coli secB gene is required for efficient export of proteins across the cytoplasmic membrane. The studies described in this report show that in wild-type growing cells, SecB protein associates with precursor forms of exported proteins, such as the periplasmic maltose-binding protein (MBP) and the outer-membrane proteins LamB and OmpA. In contrast, the cytoplasmic protein β -galactosidase was not found in association with SecB. Pulse--chase analysis showed that the SecB--precursor MBP complex was short lived, as expected for a complex that represents an intermediate in the protein-export pathway. The results support the hypothesis that SecB protein associates with exported protein precursors in the cytoplasm and dissociates prior to or during translocation of precursors across the cell membrane.

Page Thumbnails

  • Thumbnail: Page 
5320
    5320
  • Thumbnail: Page 
5321
    5321
  • Thumbnail: Page 
5322
    5322
  • Thumbnail: Page 
5323
    5323
  • Thumbnail: Page 
5324
    5324