Type VII ABC transporters: New biology in the bacterial cell envelope

Secondary Supervisor(s): Professor Phill Stansfeld

University of Registration: University of Warwick

BBSRC Strategic Research Priority: Understanding the Rules of Life (Microbiology, Structural Biology)

Project Outline

Type VII ABC transporters are ATP-powered membrane proteins that perform essential functions in the bacterial cell envelope

Key examples of Type VII ABC transporter systems include the FtsEX-EnvC system that regulates the activity of peptidoglycan amidases in the bacterial periplasm (1,2), the MacAB-TolC efflux pump responsible for toxin secretion and antibiotic efflux (3), and the LolCDE-LolA lipoprotein trafficking system that shuttles lipoproteins between the inner and outer membranes (4).

Despite their importance, many novel Type VII ABC transporter systems remain to be characterised.In this PhD project, we will explore unusual Type VII ABC transporters from Mycobacterium tuberculosis, Vibrio cholera and Listeria monocytogenes. We are particularly interested in systems linked to bacterial virulence or suggest novel biological functions in the cell envelope.

The project will suit students interested in structural biology, antimicrobial resistance or the bacterial cell envelope.I am especially interested to hear from students that wishing to explore frontier bioscience and are keen to make new discoveries in bacterial physiology.

References

1. Cook et al (2023) Activator-induced conformational changes regulate division-associated peptidoglycan amidases.Proceedings of the National Academy of Sciences 120, e2302580120 https://doi.org/10.1073/pnas.2302580120

2. Cook et al (2020) Insights into bacterial cell division from a structure of EnvC bound to the FtsX periplasmic domain. Proceedings of the National Academy of Sciences 117, 28355-28365 https://doi.org/10.1073/pnas.2017134117

3. Crow et al (2017) Structure and mechanotransmission mechanism of the MacB ABC transporter superfamily. Proceedings of the National Academy of Sciences 114, 12572-12577 https://doi.org/10.1073/pnas.1712153114

4. Kaplan et al (2018) Insights into bacterial lipoprotein trafficking from a structure of LolA bound to the LolC periplasmic domain. Proceedings of the National Academy of Sciences 115, E7389-E7397 https://doi.org/10.1073/pnas.1806822115

Tripartite efflux pumps from pathogenic bacteria

Secondary Supervisor(s): Professor Phill Stansfeld

University of Registration: University of Warwick

BBSRC Strategic Research Priority: Understanding the Rules of Life (Microbiology, Structural Biology)

Project Outline

Tripartite efflux pumps are complex membrane-integral nanomachines that span both the inner and outer membranes of Gram-negative bacteria.

Some of the best understood tripartite pumps are MacAB-TolC, EmrAB-TolC and AcrABTolC which are responsible for antibiotic resistance and secretion.

Many more tripartite pumps can be identified in bacterial genomes due to the sequence characteristics of the adaptors, which are typically encoded in operons alongside a cognate transporter.

Since the recent revolution in protein structure prediction (AlphaFold) we have computationally identified several putative tripartite efflux pumps that are predicted to be structurally distinct from the best-studied pumps.

In this PhD project, we will experimentally investigate novel efflux pumps from E. coli, A. baumanii and P. aeruginosa. We are particularly interested in tripartite efflux pumps that are structurally or mechanistically novel, especially where they can be linked to antimicrobial resistance or infection.

The project will suit students interested in structural biology, antimicrobial resistance or the bacterial cell envelope. I am especially interested to hear from students that want to explore frontier bioscience and are keen to make new discoveries in bacterial physiology.

About the Crow Lab

The Crow lab uses structural biology and microbiology to tackle fundamental questions of how bacteria divide and defend themselves against antibiotics.

Recent publications from our lab include structural and mechanistic studies of the FtsEX-EnvC-Amidase cell division system (1,2) and development of a photostable fluorescent protein (3).

1. Cook et al (2023) Activator-induced conformational changes regulate division-associated peptidoglycan amidases. Proceedings of the National Academy of Sciences 120, e2302580120 https://doi.org/10.1073/pnas.2302580120

2. Cook et al (2020) Insights into bacterial cell division from a structure of EnvC bound to the FtsX periplasmic domain. Proceedings of the National Academy of Sciences 117, 28355-28365 https://doi.org/10.1073/pnas.2017134117

3. Ivorra-Molla et al. (2023) A monomeric StayGold fluorescent protein. Nature Biotechnology 42, 1368–1371 https://doi.org/10.1038/s41587-023-02018-w