# CAPSULE SYNTHESIS, DIVISION, AND RADIATION SENSITIVITY

> **NIH NIH R01** · UNIVERSITY OF CHICAGO · 1988 · $201,862

## Abstract

The long term objectives of this research are to understand the molecular
basis of cell division (septum formation) and its inhibition by
DNA-damaging agents (ultraviolet light, nalidixic acid, nitrofurantoin)
that induce a distress response (the SOS response) in Escherichia coli.
Other closely related objectives are to understand the details of
intracellular protein breakdown and overproduction of capsular
polysaccharide.  Cell division, ultraviolet radiation, and proteolysis
studies in bacteria may provide basic answers that are applicable to
solving human cancer which involves the heritable loss of control of cell
division.  Use of antibiotics that interfere with cell division in these
studies (penicillins, cephalosporins) may also provide important basic
information useful in designing new antibiotics.  Capsular polysaccharides
are important determinants of virulence for a number of bacteria that are
pathogenic for humans.  The specific aims are:

1. Study in vivo proteolysis and enzymes of capsular polysaccharide
synthesis regulated by the CapR (Lon) ATP hydrolysis-dependent protease.
This will be done by recloning the capR gene so that it is under lac
operator control.  The alteration of enzymes of capsular polysaccharide
synthesis and degradation or synthesis of proteins after switching the CapR
ATP hydrolysis-dependent protease on or off will be determined by measuring
the enzymes spectrophotometrically and the polypeptides by two dimensional
gels with autoradiography.  Polypeptides detected as unstable will be
tested directly using the pure CapR ATP hydrolysis dependent protease.

2. Clone the equivalent of the E. coli K-12 1on (capR) gene from
Salmonella, Shigella and Caulobacter and purify and measure the enzymatic
and DNA binding activities of the corresponding proteins by techniques
previously developed.

3. Identify, localize, purify and determine the activity of proteins
specified by genes involved in cell division.  The genes known as ftsA,
ftsQ, sulB (ftsZ, sfiB), and sulA (sfiA) and ftsI (pbp3, sep) are those
being studied.  Recloning, membrane fractionation and protein purification
techniques will be applied.

4. Purify the major outer membrane-localized Ompt protein and its precursor
and determine the N-terminal amino acid sequence of both.  Determine the
proteolytic specificity of OmpT protein which is thought to be a
trypsin-like enzyme that processes pro-OmpT protein to OmpT protein.

## Key facts

- **NIH application ID:** 3124325
- **Project number:** 5R01AI006966-23
- **Recipient organization:** UNIVERSITY OF CHICAGO
- **SAM.gov UEI:** ZUE9HKT2CLC9
- **Principal Investigator:** ALVIN MARKOVITZ
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $201,862
- **Award type:** 5
- **Project period:** 1979-05-01 → 1990-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3124325

## Citation

> US National Institutes of Health, RePORTER application 3124325, CAPSULE SYNTHESIS, DIVISION, AND RADIATION SENSITIVITY (5R01AI006966-23). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3124325. Licensed CC0.

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