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Fatty acid synthesis is essential for bacterial viability. Thus, fatty acid synthases (FASs) represent effective targets for antibiotics. Nevertheless, multidrug-resistant bacteria, including the human opportunistic bacteria, <i>Acinetobacter baumannii,</i> are emerging threats. Meanwhile, the FAS pathway of <i>A. baumannii</i> is relatively unexplored. Considering that acyl carrier protein (ACP) has an important role in the delivery of fatty acyl intermediates to other FAS enzymes, we elucidated the solution structure of <i>A. baumannii</i> ACP (AbACP) and, using NMR spectroscopy, investigated its interactions with β-ketoacyl ACP synthase III (AbKAS III), which initiates fatty acid elongation. The results show that AbACP comprises four helices, while Ca²⁺ reduces the electrostatic repulsion between acid residues, and the unconserved F47 plays a key role in thermal stability. Moreover, AbACP exhibits flexibility near the hydrophobic cavity entrance from D59 to T65, as well as in the α₁α₂ loop region. Further, F29 and A69 participate in slow exchanges, which may be related to shuttling of the growing acyl chain. Additionally, electrostatic interactions occur between the α₂ and α₃-helix of ACP and AbKAS III, while the hydrophobic interactions through the ACP α₂-helix are seemingly important. Our study provides insights for development of potent antibiotics capable of inhibiting <i>A. baumannii</i> FAS protein–protein interactions.