# Dynamic characterization of outer-membrane-protein biogenesis by the BAM and TAM complexes

> **NIH NIH R01** · GEORGIA INSTITUTE OF TECHNOLOGY · 2020 · $285,367

## Abstract

Project Summary/Abstract
Infectious diseases are the second leading cause of death in the world. With novel classes of antibiotic drugs
virtually nonexistent, and the resistance of pathogenic bacteria to current ones increasing rapidly, the develop-
ment of new approaches is becoming an imperative for advancing human health efforts. Molecular modeling
will play an essential role in these new approaches, due to the fundamentally atomic-scale nature of the critical
structures, processes, and interactions underlying the function of both bacterial proteins and antibacterial agents.
In order to illuminate these structures and processes, the PI will focus on a deﬁning feature of Gram-negative
bacteria, namely their second, outer membrane, and how integral membrane proteins are inserted there. These
outer-membrane proteins (OMPs), practically all of which belong to a speciﬁc class known as -barrels, utilize
two key systems for insertion: the BAM system, essential for viability, and the related TAM system, necessary
for virulence. Exploiting these systems as antibacterial targets requires a comprehensive understanding of the
relationship between structure, dynamics, and function. In the ﬁrst aim, a novel mechanism in which the key
component of each system, BamA and TamA, respectively, catalyzes insertion through augmentation of its own
 -barrel will be evaluated. Intermediate states of insertion will be generated in molecular dynamics simulations
and assayed experimentally through both disulﬁde cross-linking and electrophysiology measurements. In the
second aim, how BamA and TamA perturb the membrane, itself an active participant in the insertion process, will
be determined. Simulations have indicated the existence of a membrane defect that forms due to an unusually
thin and unstable part of the -barrel of BamA; mutations to alter this perturbation, and presumably decrease
OMP insertion efﬁciency, will be predicted in silico and tested in vivo. Finally, in the third aim, the dynamics of
BamA and TamA as well as BamA's interactions with other BAM components will be characterized. Based on
the conformational changes observed, small-molecule drug candidates will be selected that limit conformational
ﬂexibility and/or inhibit binding of BamA or TamA to other complex members. These candidates will then be tested
experimentally for antibacterial activity.

## Key facts

- **NIH application ID:** 9963325
- **Project number:** 5R01GM123169-04
- **Recipient organization:** GEORGIA INSTITUTE OF TECHNOLOGY
- **Principal Investigator:** James C. Gumbart
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $285,367
- **Award type:** 5
- **Project period:** 2017-09-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9963325

## Citation

> US National Institutes of Health, RePORTER application 9963325, Dynamic characterization of outer-membrane-protein biogenesis by the BAM and TAM complexes (5R01GM123169-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9963325. Licensed CC0.

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