Discovery, structural characteristics and evolutionary analyses of functional domains in Acinetobacter baumannii phage tail fiber/spike proteins

作者：Shenshen Liu, Tao Lei, Yujing Tan, Xiaoyi Huang, Wenxin Zhao, Huanhuan Zou, Jianhui Su, Ji Zeng, Haiyan Zeng · 发表于：BMC Microbiology · 年份：2025 · DOI：10.1186/s12866-025-03790-2 · 被引用次数：27 · 研究领域：Bacteriophages and microbial interactions、Monoclonal and Polyclonal Antibodies Research、RNA and protein synthesis mechanisms

BACKGROUND: The global rise in multidrug-resistant Acinetobacter baumannii infections poses a significant healthcare challenge. Bacteriophage offer a promising alternative to antibiotics for treating A. baumannii infections. Phage tail fiber and spike proteins are essential for host recognition, with some exhibiting depolymerase activity that aids in degrading the bacterial cell wall, facilitating infection. Detailed studies of the functional domains responsible for depolymerase activity and receptor-binding in phage tail fiber/spike proteins are a crucial step toward developing effective phage treatments. RESULTS: A total of 32 functional domains were identified across 313 tail fiber and spike proteins from 204 publicly available Acinetobacter baumannii phages using InterPro and AlphaFold3. Domains associated with depolymerase function were Pectin lyase-like domain (PLD), phage_tailspike_middle domain (PTMD), Transglycosidases domain (TGD), and SGNH hydrolase domain (SHD). These domains were primarily found in phages from the Autographiviridae family, specifically within the Friunavirus genus. The predominant PLD domain displayed high variability, with its sequence conserved only in a 25-amino-acid region among two closely related fiber/spike protein lineages. All enzymatic domains exhibit high sequence diversity yet retain structural stability, which is essential for enzymatic function. As for receptor-binding domains, four types of pyocin_knob domains (PKD) were initially ...