# Analysis of E. coli ribonucleases and RNA metabolism

> **NIH NIH R01** · UNIVERSITY OF GEORGIA · 2020 · $337,500

## Abstract

Project Summary
Although numerous ribonucleases have been identified over the past 40 years, most have been
associated primarily with the biological reaction that was used for their identification. Thus an
enzyme like RNase P has been assumed to be strictly involved tRNA processing. Likewise the
RNase Z family of enzymes has also been thought to be only involved in tRNA processing,
while RNase III type proteins, at least in prokaryotes are considered rRNA maturation enzymes.
However, more recent experiments have demonstrated that most of these ribonucleases have
multiple functions in the cell. When one carefully looks at what is known about the pathways of
rRNA maturation, tRNA processing and mRNA decay, it becomes clear that many of the
existing models for these processes are too simplistic and in some cases probably incorrect. In
addition, not much is known regarding the enzymatic overlap among these important pathways.
For example, during the current grant period, we have demonstrated the existence of multiple
new pathways for tRNA processing that require either RNase P or polynucleotide
phosphorylase (PNPase) as the first step in processing tRNA precursors rather than RNase E.
Furthermore, we hve shown a link between polyadenylation and functional tRNA levels as well
as the existence of a previously unidentified endonuclease. Accordingly, this application
describes a series of experiments that will focus on developing a more complete understanding
of post-transcriptional RNA metabolism in the model prokaryote, Escherichia coli. Our approach
will be to use a combination of unique bacterial strains, high density tiling microarrays as well as
other molecular biological, biochemical and bioinformatic approaches. Specific experiments
include: 1. Transcriptome-wide analysis of the initiation of mRNA processing and decay;
2. Detailed analysis of the role of tRNA nucleotidyl transferase in RNA metabolism and
identification of structural features for exonuclease-independent tRNA maturation;3.
Characterization of YhgF endonuclease activity and the molecular mechanisms of RNase III-
independent 30S rRNA processing. With the increasing prevalence of antibiotic resistant
bacteria, the need to better understand the overall mechanism of post-transcriptional RNA
metabolism is becoming increasingly important. Information gained from this work could be
instrumental in the identification of potential new drug targets.

## Key facts

- **NIH application ID:** 9980912
- **Project number:** 5R01GM081554-12
- **Recipient organization:** UNIVERSITY OF GEORGIA
- **Principal Investigator:** Sidney R. Kushner
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $337,500
- **Award type:** 5
- **Project period:** 2008-03-15 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9980912

## Citation

> US National Institutes of Health, RePORTER application 9980912, Analysis of E. coli ribonucleases and RNA metabolism (5R01GM081554-12). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9980912. Licensed CC0.

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