Date of Completion


Document Type

Honors College Thesis



Thesis Type

Honors College

First Advisor

Scott Morrical

Second Advisor

Matthias Brewer


Cyanophage = a virus which infects cyanobacteria


Cyanobacteria are essential to the biosphere for their primary production of oxygen and their fixation of carbon and nitrogen. The evolution of cyanobacteria in the ocean is controlled by infectious cyanophages. The cyanophage S-RSM4 carries a copy of glucose 6-phosphate dehydrogenase (G6PDH), a photosynthetic enzyme homologous to that of its host, Synechococcus sp. W8103. Both G6PDH homologs were cloned and expressed. The viral enzyme was purified, and its kinetic and mechanistic properties were investigated. It is likely that SRSM4 encodes this enzyme to continue production of ribose 5-phosphate and NADPH during infection, independent of the host’s homeostatic constraints. A continued effort to understand this unique parasitism is pertinent to understanding the ocean’s microbiome as a whole.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.