To access this work you must either be on the Smith College campus OR have valid Smith login credentials.

On Campus users: To access this work if you are on campus please Select the Download button.

Off Campus users: To access this work from off campus, please select the Off-Campus button and enter your Smith username and password when prompted.

Non-Smith users: You may request this item through Interlibrary Loan at your own library.

Publication Date


Document Type

Honors Project


Biological Sciences


Bacteriocins, Colicins, Antibiotics, Drug resistance, Antibiotic resistance


Considering the rise of antibiotic resistance and our growing understanding of the role our microbiome plays in our health, it is clear that we need a new approach to treating infection. Killing only specific pathogens will be a crucial characteristic of these future antibiotics. Colicins, a family of bacterially secreted proteins called bacteriocins that kill related strains of bacteria, achieve this target specificity in nature. Colicins are unusual in that they seem to display both functional and structural modularity. Indeed, the three steps of colicin function appear to have corresponding structural domains: the receptor-binding (R) domain, the translocation (T) domain, and the killing (K) domain. The receptor-binding and translocation domains provide the target specificity of the colicin and have potential as a shuttle mechanism into specific targets. The limits of colicin modularity and the extent to which these domains can function independently, however, are unknown. This study aims to further define the limits of the colicin modularity by tethering two different foreign domains – the killing domain of colicin M and Green Flourescent Protein (GFP) – onto the translocation and receptor-binding domains of colicin K. Observing the retained activity of these two chimeras (TRK*KM and TRK*GFP) would further define the potential of colicins as tools in the development of target-specific antibiotics. Although the functionality of the receptorbinding and translocation domains remain unknown, the killing domain of colicin M retains killing activity, demonstrating its ability to function when tethered to foreign domains.




60 p. : col. ill. Honors project-Smith College, Northampton, Mass., 2012. Includes bibliographical references (p. 56-59)