Working with the Wu Orr Lab

Hello! My name is Carl Soderstrom, and I am a rising sophomore majoring in Biochemistry and French. This summer, I will be on campus working as a Greg Call intern for Professor Wu Orr. Our lab is interested in how bacteria utilize small proteins of about 50 amino acids or shorter to respond to stressors in their environment. The small protein I will be working with this summer is AcrZ.

Crystal structure of the AcrAB-TolC complex from:

AcrZ is a 49-amino acid long alpha-helical transmembrane protein that is important for the function of a bacterial membrane pump that contributes to antibiotic resistance in Escherichia coli by binding to the efflux pump complex that is AcrAB-TolC. With the rise of antibiotic-resistant bacteria, it is becoming more and more important that we learn how antibiotic resistance functions in bacteria as well as how we can deal with pesky multidrug-resistant strains and species.

My project this summer is to screen mutant forms of AcrZ and see how the changes in the amino acids affect the pump’s productivity and the interactions between AcrZ and AcrB. I plan on growing E. Coli with a pBAD plasmid. pBAD is a relatively small double-stranded circular strand of DNA that contains parts of the arabinose operon and the gene of interest. The arabinose promoter allows for easy regulation of gene expression and easy tracking of protein-protein interactions. Once I grow the bacteria, I will then electroporate the cells and perform multiple tests to ensure that the plasmids were able to make it into the cells during electroporation. Electroporation is the process by which we introduce DNA into bacteria by pulsing them with electricity to disrupt the cell membrane.

Example of electroporation from

Once we are sure that the plasmids are in, we will perform a “miniprep” to extract the DNA from the E. Coli, send them out to sequencing, and analyze the results.

But beyond research, I am very excited to finally be able to explore Amherst and Northhampton. I have already gotten my order down at Mogee Tee and Momo’s. I am also excited to continue taking care of my plants which include chili peppers, lavender, spider plants, and cacti.