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Biochemistry, Biophysics, and Structural Biology

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1997

Escherichia coli

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Both An N-Terminal 65-Kda Domain And A C-Terminal 30-Kda Domain Of Seca Cycle Into The Membrane At Secyeg During Translocation, Jerry Eichler, William Wickner Apr 1997

Both An N-Terminal 65-Kda Domain And A C-Terminal 30-Kda Domain Of Seca Cycle Into The Membrane At Secyeg During Translocation, Jerry Eichler, William Wickner

Dartmouth Scholarship

SecA, a 102-kDa hydrophilic protein, couples the energy of ATP binding to the translocation of preprotein across the bacterial inner membrane. SecA function and topology were studied with metabolically labeled [35S]SecA and with inner membrane vesicles from cells that overex- pressed SecYEGDFyajC, the integral domain of preprotein translocase. During translocation in the presence of ATP and preprotein, a 65-kDa N-terminal domain of SecA is protected from proteolytic digestion through insertion into the mem- brane, as previously reported for a 30-kDa C-terminal domain [Economou, A. & Wickner, W. (1994) Cell 78, 835–843]. Insertion of both domains occurs at saturable SecYEGDFyajC sites …


I2b Is A Small Cytosolic Protein That Participates In Vacuole Fusion, Paul Slusarewicz, Zuoyu Xu, Kimberly Seefeld, Albert Haas, William T. Wickner Mar 1997

I2b Is A Small Cytosolic Protein That Participates In Vacuole Fusion, Paul Slusarewicz, Zuoyu Xu, Kimberly Seefeld, Albert Haas, William T. Wickner

Dartmouth Scholarship

Saccharomyces cerevisiae vacuole inheritance requires two low molecular weight activities, LMA1 and LMA2. LMA1 is a heterodimer of thioredoxin and protease B inhibitor 2 (IB2). Here we show that the second low molecular weight activity (LMA2) is monomeric IB2. Though LMA2 / IB2 was initially identified as a protease B inhibitor, this protease inhibitor activity is not related to its ability to promote vacuole fusion: ( i ) Low M r protease B inhibitors cannot substitute for LMA1 or LMA2, ( ii ) LMA1 and LMA2 promote the fusionof vacuoles from a strain that …