# GENETICS & MOLECULAR BIOLOGY OF CHEMOTAXIS IN B SUBTILIS

> **NIH NIH R01** · UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN · 1988 · $145,602

## Abstract

In chemotaxis by Bacillus subtilis, the information that attractant has
bound to chemoreceptors is transduced along a pathway, which includes loss
of methyl groups from the methyl-accepting chemotaxis proteins (MCPs), and
ultimately results in a transient increase of counterclockwise rotation by
the flagella.  It is very important to trace this pathway, to discover what
proteins are involved and what their functions are.  B. subtilis is perhaps
the best organism for this work since we have, using purified
methyltransferase and methylesterase, shown that attractants retard
methylation and strongly enhance demethylation of MCPs in vitro.  Only in
B. subtilis have these enzymes been purified to homogeneity.  We have also
developed two complementation systems and have obtained evidence for over
twenty new genes.  Thus, the stage is now set to investigate proteins that
modulate methylation reactions.  Using this system, we will explore the
mechanism of several novel events induced by attractant:  transfer of
methyl groups between MCPs, turnover of methyl groups on MCPs, and transfer
to an intermediate acceptor before formation of methanol.  The last step is
blocked by repellents and is the first biochemical handle on their
mechanism of action.  Isolation and characterization of mutants, including
those containing a transposon that may express Beta-galactosidase, and
cloning the chemotaxis genes will greatly assist us.  Once the genes are
cloned, we will carry out a restriction analysis of chromosomal segments
and correlate the genetic and physical maps.  We will express the genes in
E. coli minicells as radioactive proteins so that we can ascertain their
size and hydrophobicity and search for protein/protein interactions,
especially with the switch, which controls direction of flagellar
rotation.  By second-site reversion studies, we will also seek evidence for
such interactions.  Our understanding of the MCPs, which represent our
major biochemical handle on chemotaxis, is hampered by lack of mutants and
insufficient gene expression and, using the techniques of molecular
biology, we exprect to remedy this.  Our knowledge, not only of the MCPs,
but of over twenty other chemotaxis proteins, will be enhanced by mapping
and complementing the mutants and by varying levels of genes expression.
Armed with a uniquely suitable in vitro system for evaluation the effects
of chemotaxis proteins, we believe that a renewed emphasis on genetics and
molecular biology will prove especially fruitful.

## Key facts

- **NIH application ID:** 3129942
- **Project number:** 5R01AI020336-06
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
- **SAM.gov UEI:** Y8CWNJRCNN91
- **Principal Investigator:** George W. Ordal
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $145,602
- **Award type:** 5
- **Project period:** 1983-08-01 → 1991-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3129942

## Citation

> US National Institutes of Health, RePORTER application 3129942, GENETICS & MOLECULAR BIOLOGY OF CHEMOTAXIS IN B SUBTILIS (5R01AI020336-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3129942. Licensed CC0.

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