The opportunistic pathogen Acinetobacter baumannii is commonly associated with hospital-acquired bacteremia and respiratory infections. Antibiotic resistance is rapidly emerging in A. baumannii, posing such a risk to global health that the World Health Organisation has listed it as a priority 1 critical organism where new antibiotic agents are urgently required. Many strains of A. baumannii express a type VI secretion system (T6SS). This molecular machine delivers antibacterial toxins directly into competitor bacteria; providing T6SS-positive cells with a competitive advantage in certain niches. To prevent self-toxicity the T6SS-poitive cells must express cognate immunity proteins that directly bind and neutralise effectors. One such effector-immunity pair from A. baumannii strain AB307 is the Type VI DNase effector 16 (Tde16) and its cognate DNase immunity protein (Tdi16). To confirm the activity of Tde16, attempts were made to express and purify the predicted DNase domain of Tde16 in a bacterial expression system; however, protein toxicity resulted in death of the E. coli expression strain. Therefore, guided by homology to other DNases, a double alanine mutant at the predicted active site was constructed (AHH to AAA) to produce Tde16AAA. Tde16AAA was non-toxic when expressed in E. coli and purification confirmed the protein was monomeric and capable of binding DNA. Purification of full length Tdi16 showed that the two proteins directly interact with a likely binding stoichiometry of 1:1 and that presence of Tdi16 disrupts Tde16AAA DNA binding. Currently, further investigations into the DNA binding properties of Tde16AAA are being conducted, as well as crystal trials with the aim to solve the structure of Tde16AAA, both alone and in combination with Tdi16. Exploring effector/immunity interactions may allow for manipulation and treatment of A. baumannii infections in future. The effectors alone may also represent novel antimicrobial agents to aid in combating antimicrobial resistance.