# STRUCTURE AND FUNCTION OF THE SV40 TUMOR ANTIGEN

> **NIH NIH R01** · UNIVERSITY OF DELAWARE · 1990 · $171,233

## Abstract

We have previously mapped and characterized the DNA-binding
domain of the SV70 tumor (T) antigen.  Our data demonstrate that
a region mapping between residues 131 to 371 is important for
replication origin-specific DNA binding.  By protease digestion
experiments, we have also shown that a "core" region mapping
from approximately 140 to 281 is tightly associated with the
DNA.  Genetic data from other labs indicate that the essential
sequences within this core region map from 140 to about 260.
Together, these findings define the minimal region of T antigen
which is needed to bind to the replication origin.  As part of this
proposed work, we plan to identify the sequences within the core
element that are essential for the proper structure of the DNA-
binding region and for making contacts with the DNA.  This will
be done by testing the activity of mutants with specific amino
acid substitutions.

Beside DNA-binding, the SV40 T antigen has several other
activities that are involved in virus DNA replication.  These
include an ATPase, a single-strand DNA-binding activity, a
helicase and an origin-specific DNA unwinding activity.  Although
the origin DNA-binding and ATPase domains have been carefully
mapped, there is presently very little information about the
regions that are responsible for the other three activities.  We
plan to map these regions by examining the in vitro activity of
various tryptic fragments.

Finally, in order to understand how the multiple functional
domains of this protein communicate and interact with one
another during viral DNA replication, we will generate various
deletion mutants and test the effect of the deletions on T antigen
function.

## Key facts

- **NIH application ID:** 3173626
- **Project number:** 5R01CA036118-06
- **Recipient organization:** UNIVERSITY OF DELAWARE
- **SAM.gov UEI:** T72NHKM259N3
- **Principal Investigator:** Daniel T. Simmons
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $171,233
- **Award type:** 5
- **Project period:** 1985-09-01 → 1993-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3173626

## Citation

> US National Institutes of Health, RePORTER application 3173626, STRUCTURE AND FUNCTION OF THE SV40 TUMOR ANTIGEN (5R01CA036118-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3173626. Licensed CC0.

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