# REPRESSOR AND ANTIREPRESSOR PROTEINS OF BACTERIOPHAGES

> **NIH NIH R01** · MASSACHUSETTS INSTITUTE OF TECHNOLOGY · 1993 · $329,115

## Abstract

Site specific DNA binding proteins play important roles in the regulation
of transcription; the replication and repair of DNA; phage and viral DNA
packaging; site-specific recombination and transposition, and
restriction-modification.  One of the goals of modem molecular biology is
to understand these processes in molecular detail.  A true understanding
of DNA recognition would allow the design of proteins that could bind to
specific sequences in cellular or viral DNA.  If such proteins could be
targeted to appropriate cells, they might be used to modulate gene
expression or viral growth and thus be valuable in the treatment of
disease.

The objective of the research described in this proposal is to understand
the relationship between the sequences and structures of repressor
proteins and their DNA recognition and gene regulatory activities . As
experimental systems, three phage repressors, P22 Arc, P22 Mnt, and the
N-terminal domain of phage lambda repressor will be studied.  Arc and Mnt
are small, homologous proteins that use the recently discovered
beta-ribbon motif for DNA recognition.  Lambda repressor is a
helix-turn-helix DNA binding protein.  Each of these systems is readily
accessible to study by a combination of protein and nucleic acid
chemistry, molecular genetics analysis, kinetic and equilibrium studies,
and X-ray crystallography, thereby allowing meaningful structure-function
studies.  X-ray crystallographic studies of protein-DNA complexes will be
combined with biochemical studies of the effects of side chain
substitution mutations on the free energy and specificity of DNA
recognition to determine the mechanisms by which remarkable specificity
changes in DNA binding can be caused by single amino acid changes.  The
mechanism by which Arc prevents or slows the isomerization of RNA
polymerase during transcription will also be addressed by a combination
of biochemical and genetic studies.  Optimal DNA binding sites will be
determined for Arc in three different structural backgrounds to determine
if quaternary structure constrains idealized DNA contacts and vice versa.

## Key facts

- **NIH application ID:** 3126885
- **Project number:** 2R01AI016892-14
- **Recipient organization:** MASSACHUSETTS INSTITUTE OF TECHNOLOGY
- **SAM.gov UEI:** E2NYLCDML6V1
- **Principal Investigator:** Robert T Sauer
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $329,115
- **Award type:** 2
- **Project period:** 1980-04-01 → 1998-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126885

## Citation

> US National Institutes of Health, RePORTER application 3126885, REPRESSOR AND ANTIREPRESSOR PROTEINS OF BACTERIOPHAGES (2R01AI016892-14). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126885. Licensed CC0.

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