# FACTORS DETERMINING PROTEIN LOCALIZATION IN E. COLI

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 1989 · $129,749

## Abstract

Studies with the gram-negative bacterium Escherichia coli have indicated
that proteins are exported to the periplasm and outer membrane of this
organism by a mechanism similar to that proposed for the initial steps of
protein secretion in eukaryotic cells.  For the past several years, our
laboratory has been extensively investigating the synthesis and secretion
of the periplasmic maltose-binding protein (MBP) of E. Coli using a
combination of genetic and biochemical approaches.  Our long term goal is
to fully understand, at the molecular level, the mechanism by which the MBP
is exported from its site of synthesis in the cytoplasm, through the
cytoplasmic membrane, to the periplasm.  The following are our specific
aims for the proposed five-year project period:  (1) We would like to
further define the functional determinants of the MBP signal peptide.  For
example, we hope to determine the absolute minimal requirements for a
signal peptide that can facilitate MBP export at a rate and efficiency
comparable to the wild-type structure.  (2) An attempt will be made to
directly demonstrate the existence of an "internal export signal" (IES)
that resides in the mature MBP, far removed from the signal peptide, and to
determine its exact role in the export process.  (3) The possibility that
important export information resides at the extreme amino-terminus of the
mature MBP also will be investigated.  (4) The pr1D gene and other genes
that we identify that are thought to encode specific components of the
cell's protein export machinery will be cloned, and the protein products
identified and characterized.  (5) We hope to use various E. coli mutants
to help us to dissect the MBP export pathway.  By blocking MBP export at
different steps, such mutants could allow us to more easily demonstrate a
direct interaction between the MBP and known components of the export
machinery at various points along this pathway.  (6) We have recently
developed an in vitro system in which precursor MBP is efficiently
synthesized, imported into inverted E. coli cytoplasmic membrane vesicles,
and processed to the mature form.  We believe that we can use this system
to gain additional insight into the MBP export process.

## Key facts

- **NIH application ID:** 3127118
- **Project number:** 5R01AI017292-10
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **SAM.gov UEI:** D3LHU66KBLD5
- **Principal Investigator:** PHILIP J BASSFORD
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $129,749
- **Award type:** 5
- **Project period:** 1980-08-01 → 1991-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3127118

## Citation

> US National Institutes of Health, RePORTER application 3127118, FACTORS DETERMINING PROTEIN LOCALIZATION IN E. COLI (5R01AI017292-10). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3127118. Licensed CC0.

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