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Open AccessJournal ArticleDOI

Alteration of the amino terminus of the mature sequence of a periplasmic protein can severely affect protein export in Escherichia coli

Ping Li, +2 more
- 01 Oct 1988 - 
- Vol. 85, Iss: 20, pp 7685-7689
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TLDR
The results suggest that the presence of two positively charged amino acids very early in the mature sequence interferes significantly with protein export and suggest a way to improve export in these cases.
Abstract
Escherichia coli alkaline phosphatase, coded for by the phoA gene, is normally translocated across the cytoplasmic membrane into the periplasm with high efficiency. We have constructed a series of derivatives of the phoA gene that code for a wild-type signal sequence but result in altered amino acid sequences at the amino terminus of the mature alkaline phosphatase. Our results suggest that the presence of two positively charged amino acids very early in the mature sequence interferes significantly with protein export. In one case, phoA2AB, the presence of the sequence Arg-Ile-Arg at the amino terminus of alkaline phosphatase results in a 50-times reduction in the export of the protein. By using oligonucleotide-directed mutagenesis, we have constructed mutant derivatives of phoA2AB that are greatly enhanced for export. In all cases, these derivatives reduce the net positive charge in the region. Our results may explain the failure of E. coli to export a number of proteins coded for by artificial constructs and suggest a way to improve export in these cases.

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Citations
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The complete general secretory pathway in gram-negative bacteria

TL;DR: The unifying feature of all proteins that are transported out of the cytoplasm of gram-negative bacteria by the general secretory pathway is the presence of a long stretch of predominantly hydrophobic amino acids, the signal sequence.
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Modular assembly of antibody genes, antibodies prepared thereby and use.

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Production of soluble recombinant proteins in bacteria

TL;DR: This review summarizes what is known about why IBs form and ways of increasing the production of soluble protein in bacterial systems and discusses possibilities for mimicking these mechanisms in bacteria via secretion, cloning of mammalian foldases, and mutation of the post-translational modification systems of the host bacteria.
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Sec- and Tat-mediated protein secretion across the bacterial cytoplasmic membrane—Distinct translocases and mechanisms

TL;DR: In bacteria, two major pathways exist to secrete proteins across the cytoplasmic membrane: the general Secretion route and the Twin-arginine translocation pathway, which catalyses the translocation of secretory proteins in their folded state.