# Mechanistic studies of nucleic acid enzymes involved in DNA replication, transcription, and innate immunity

> **NIH NIH R35** · RBHS-ROBERT WOOD JOHNSON MEDICAL SCHOOL · 2020 · $91,141

## Abstract

ABSTRACT
The overarching goal of our research is to understand the mechanisms of helicases and polymerases in
processes such as DNA replication, transcription, and role of RIG-I helicase in innate immunity. Our research
has made major contributions to understanding how these molecular motors move on nucleic acids to catalyze
DNA and RNA strand separation and synthesis. These insights can provide the basis for understanding and
treatment of diseases caused by dysregulation or malfunction of these enzymes. The unifying approach is
quantitative characterization of the enzymatic reactions using rigorous biochemical and biophysical methods
such as transient state kinetics, single molecule kinetics, computational kinetic modeling, and crystallography.
Integration of structural and functional studies allows development of a complete mechanistic picture. The
elegantly simple phage T7 enzymes allowed us to probe replication reactions with unprecedented temporal
and spatial resolution, to develop new biophysical tools that correlate structure with function, and to propose
new mechanisms that serve as a basis for studying more complex mitochondrial replication and transcription
enzymes. Mitochondrial DNA deletions caused by defects in mitochondrial helicase and DNA polymerase
affect energy production and result in a wide variety of neuromuscular diseases. Hence, in depth
understanding of the enzymatic mechanisms of the mitochondrial DNA enzymes are critically needed. Our
research on T7 and mitochondrial DNA replication will address key gaps in understanding the structure of the
replisome, the proofreading mechanism of the DNA polymerase, and the DNA recombination activities of
mitochondrial DNA helicase Twinkle. Our research on mitochondrial DNA transcription will provide mechanistic
insights into the initiation mechanism, roles of the transcription factors, and address challenges in solving the
structure of the initiation complex. Recently, we ventured into investigating the roles of RNA helicases in innate
immunity by biochemically and structurally characterizing the RIG-I family of helicases. The RIG-I family of
helicases are the cytoplasmic detectors of RNA viral infections, e.g. Dengue fever, West Nile, influenza, and
hepatitis C. Our research will address key gaps in understanding the essential role of RIG-I helicases in
initiating innate immunity by identifying crucial viral RNA recognition features, how viruses evade detection,
and mechanisms that activate RIG-I. We will also address challenges in understanding the role of ATPase in
RIG-I activation. This research will provide the mechanistic framework to quantitatively model the reactions of
replication, transcription, and pathogen recognition that will guide in the development of therapies for human
diseases including cancer, antiviral, and antimicrobial agents.

## Key facts

- **NIH application ID:** 10132675
- **Project number:** 3R35GM118086-05S1
- **Recipient organization:** RBHS-ROBERT WOOD JOHNSON MEDICAL SCHOOL
- **Principal Investigator:** SMITA S PATEL
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $91,141
- **Award type:** 3
- **Project period:** 2016-05-01 → 2021-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10132675

## Citation

> US National Institutes of Health, RePORTER application 10132675, Mechanistic studies of nucleic acid enzymes involved in DNA replication, transcription, and innate immunity (3R35GM118086-05S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10132675. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*