CRISPR Systems are adaptive immune systems in bacteria used to defend against mobile genetic elements such as bacteriophages, or bacterial viruses, and plasmids. They use a protein complexed with a guide RNA to target the protein to a foreign invader and neutralize it by cleaving its genetic information. In order to survive and keep infecting bacteria, bacteriophages likewise have developed machinery used to inhibit CRISPR immunity in the form of anti-CRISPR (Acr) proteins. The type IV-A system is a recently discovered and characterized system by the Jackson lab. It has been shown to defend against plasmids, but further data on its mechanism as well as interactions with phages is still unknown. To understand these questions better, we have conducted research into the Acrs of the type IV-A system. Here we describe the discovery and characterization of one of these proteins, AcrIVA3, which is encoded by a prophage, a bacteriophage that has inserted its genome into the chromosome of a bacteria. We discuss here the identification of this protein, as well as initial data on its structural and biochemical characterization. Further study of this Acr, as well as others and their interactions with the type IV-A system will reveal more knowledge about the type IV-A system. This will also lead us to greater understanding of the general interactions between bacteria and their pathogens.