Open AccessTargeting of GroEL to SecA on the cytoplasmic membrane of Escherichia coli
Author(s) -
Elena S. Bochkareva,
Maria E. Solovieva,
A.S. Girshovich
Publication year - 1998
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.95.2.478
Subject(s) - groel , groes , chaperonin , escherichia coli , membrane , cytoplasm , chaperone (clinical) , inner membrane , biology , membrane protein , biochemistry , biophysics , protein folding , microbiology and biotechnology , chemistry , medicine , pathology , gene
Chaperonin GroEL has been found to interact with isolated cytoplasmic membrane ofEscherichia coli . Interaction requires Mg ions, whereas MgATP inhibits, and inhibition is stronger in the presence of co-chaperonin GroES. “Heat-shock” of the membrane at 45°C destroys irreversibly its ability to bind GroEL. The binding of GroEL is characterized by saturation with a maximum of about 100 pmol GroEL bound per mg of total membrane protein, indicating a limited capacity and specificity of the membrane to bind GroEL. According to results of immunoblotting analysis and cleavable photoactivable cross-linking, a membrane target of GroEL is SecA, a protein known as a central component of the translocation machinery. Moreover, in some cases GroEL could modulate a cycle of association of SecA with the membrane by stimulating release of SecA from the membrane. A physiological role of targeting of GroEL in or close to the protein-conducting membrane apparatus is discussed.