Undergraduate Honors Theses

Thesis Defended

Spring 2017

Document Type


Type of Thesis

Departmental Honors



First Advisor

Marcelo Sousa


The β-Barrel assembly machine (BAM) catalyzes the folding and insertion of outer membrane proteins (OMP) in gram-negative bacteria. The protein complex is essential for cell survival due to its critical role in folding the vast number of outer membrane proteins. However, the mechanism by which BAM recognizes, folds, and inserts OMPs is still poorly understood. Of the five subunits in the BAM complex, only BamA and BamD are essential for cell viability. Here, a crystal structure of a BamA-BamD fusion protein from Rhodothermus Marinus is presented and shown to capture the native interaction. I also demonstrate a proof of concept in vitro OMP folding model based on an in vitro transcription translation system which could be used to probe the BAM folding mechanism. The in vitro assay could be further developed to more accurately replicate in vivo folding conditions compared to existing in vitro models.