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Stabilization of SecA ATPase by the primary cytoplasmic salt of Escherichia coli.

ABSTRACT: Much is known about the structure, function, and stability of the SecA motor ATPase that powers the secretion of periplasmic proteins across the inner membrane of Escherichia coli. Most studies of SecA are carried out in buffered sodium or potassium chloride salt solutions. However, the principal intracellular salt of E. coli is potassium glutamate (KGlu), which is known to stabilize folded proteins and protein-nucleic acid complexes. Here we report that KGlu stabilizes SecA, including its dimeric state, and increases its ATPase activity, suggesting that SecA is likely fully folded, stable, and active in vivo at 37°C. Furthermore, KGlu also stabilizes a precursor form of the secreted maltose-binding protein.

SUBMITTER: Roussel G

PROVIDER: S-EPMC6511833 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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Stabilization of SecA ATPase by the primary cytoplasmic salt of Escherichia coli.

Roussel Guillaume G Lindner Eric E White Stephen H SH

Protein science : a publication of the Protein Society 20190501 6

Much is known about the structure, function, and stability of the SecA motor ATPase that powers the secretion of periplasmic proteins across the inner membrane of Escherichia coli. Most studies of SecA are carried out in buffered sodium or potassium chloride salt solutions. However, the principal intracellular salt of E. coli is potassium glutamate (KGlu), which is known to stabilize folded proteins and protein-nucleic acid complexes. Here we report that KGlu stabilizes SecA, including its dimer ...[more]

PMID: 30968480

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