Undergraduate Honors Thesis Projects

Date of Award

Spring 3-20-2026

Document Type

Honors Paper

Degree Name

Biology-BS

Department

Biology & Earth Science

Advisor

Dr. Jennifer Bennett

First Committee Member

Dr. Jennifer Bennett

Second Committee Member

Dr. John Tansey

Third Committee Member

Dr. Meredith Frey

Keywords

Microbiology, Streptomyces, Spore Shape, Suppressors, Duquesne, Proteins

Subject Categories

Biology | Cell and Developmental Biology | Cell Biology | Higher Education

Abstract

SsdA is required for proper spore cell wall formation for Streptomyces venezuelae, which is a filamentous soil bacterium. SsdA (spore shape determinant protein A) is a large integral membrane protein of unknown function. A known feature of SsdA is that it is predicted to have a large central cytoplasmic domain (40% of the protein) flanked by two transmembrane domains. This pilot study began by using two approaches to gain knowledge about the function of the cytoplasmic domain of SsdA. The first approach was to use a random library in a Bacterial Two-Hybrid screen to find cytoplasmic domain interaction partners. The second approach was to isolate a strain expressing a fusion of the cytoplasmic domain of a promiscuous biotin ligase for an in vivo proximity-labeling assay to identify proteins in a putative complex with SsdA. Plasmid tools generated in both approaches were and are continuing to be used in subsequent experiments. These complementary protein-protein interaction assays may provide a better understanding of SsdA's function. Another aspect of this project was to identify suppressor mutations that compensate for the loss of SsdA function. Suppressor mutations that restored an exploration phenotype on high-salt medium in a ssdA deletion strain revealed a gene in common with many of the suppressor mutant strains in this study. This research provides a better understanding of SsdA and other roles SsdA may be involved in outside of spore shape determination.

Licensing Permission

Copyright, all rights reserved. Fair Use

Acknowledgement 1

1

Acknowledgement 2

1

Download

Share

COinS