# YloC, a new ribonuclease of Bacillus subtilis

> **NIH NIH R01** · ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI · 2024 · $22,434

## Abstract

PROJECT SUMMARY: Our laboratory has, for many years, studied the essential process of mRNA decay in
the model Gram-positive bacterium, Bacillus subtilis. We have identified several ribonuclease (RNase) enzymes
of B. subtilis and have elucidated the role they play in mRNA turnover. The viability of a B. subtilis strain lacking
all of the known 3’-to-5’ exoribonucleases prompted us to pursue identification of additional RNase activities.
Using classic protein biochemistry, we recently identified a novel RNase, named YloC. YloC is an
endoribonuclease with a hexameric structure, an unusual characteristic that is shared with only one other RNase:
the Nsp15 protein of the SARS-CoV family. Initial experiments suggest that, although YloC has ribonuclease
activity in vitro, it may function as an adapter for RNA interactions in vivo. Although proteins with significant
homology to YloC are widespread in bacterial species, there is no published information on the structure of any
member of this protein family. The current proposal seeks to elucidate the structure and function of YloC, and
the related Escherichia coli YicC, as follows:
 • Mutagenize highly conserved residues of YloC/YicC to determine the effect on several properties –
 including ribonuclease activity, RNA binding, and structure – and to clarify functional domains of the
protein.
 • Identify high-affinity RNA ligands of YicC via SELEX procedures with random-sequence
 oligonucleotides and with genomic RNA sequences.
 • Characterize how the strong interaction of YloC with E. coli polynucleotide phosphorylase (PNPase)
 acts in small RNA (sRNA) regulation in E. coli and possibly in B. subtilis.
 • Determine the three-dimensional structure of the highly homologous E. coli YicC protein bound to an
 RNA substrate, as well as the structure of YloC and/or its homologs from thermophilic bacterial species.
 This work will build on an initial determination of the structure of YicC.
RELEVANCE: Ribonucleases play essential roles in RNA turnover and processing. A thorough understanding
of the proteins that bind to and act enzymatically on RNA molecules will enable design of antimicrobial agents
that disrupt such proteins and thereby interfere with bacterial cell growth.
Project Summary has not changed since original application.

## Key facts

- **NIH application ID:** 11100491
- **Project number:** 3R01GM147211-02S1
- **Recipient organization:** ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
- **Principal Investigator:** DAVID H BECHHOFER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $22,434
- **Award type:** 3
- **Project period:** 2023-08-01 → 2027-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11100491

## Citation

> US National Institutes of Health, RePORTER application 11100491, YloC, a new ribonuclease of Bacillus subtilis (3R01GM147211-02S1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/11100491. Licensed CC0.

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