# Siderophore secretion by Mycobacterium tuberculosis

> **NIH NIH R21** · UNIVERSITY OF ALABAMA AT BIRMINGHAM · 2021 · $238,240

## Abstract

Project Summary - Siderophore secretion by Mycobacterium tuberculosis
To counteract the iron limitation in the host, Mtb secretes siderophores, small molecules with
high iron-binding affinities called mycobactins (MBT) and carboxy-mycobactins (cMBT). We
discovered that the two small membrane proteins MmpS4 and MmpS5 interact with the large
efflux pumps MmpL4 and MmpL5 to form the inner membrane components of a novel
siderophore secretion system that is different from all other known bacterial siderophore
secretion systems. This system is also used by Mtb to recycle siderophores. Interruption of
siderophore recycling by deleting the inner membrane components leads to self-poisoning of
Mtb and completely eliminates the ability of Mtb to replicate in mice. However, several
components of the siderophore secretion system are still unknown. In this proposal we will use
complimentary genetic, biochemical and biophysical methods to identify and characterize novel
proteins involved in siderophore secretion by Mtb.

## Key facts

- **NIH application ID:** 10128072
- **Project number:** 1R21AI151239-01A1
- **Recipient organization:** UNIVERSITY OF ALABAMA AT BIRMINGHAM
- **Principal Investigator:** MICHAEL NIEDERWEIS
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $238,240
- **Award type:** 1
- **Project period:** 2021-04-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10128072

## Citation

> US National Institutes of Health, RePORTER application 10128072, Siderophore secretion by Mycobacterium tuberculosis (1R21AI151239-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10128072. Licensed CC0.

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