Abstact

Xanthomonas bacteria are responsible for disease outbreaks in several hundred plant species, causing significant economic losses. Xanthomonas phages have emerged as a promising biocontrol strategy in managing various important plant diseases caused by Xanthomonas bacteria. However, structural information for Xanthomonas phages has remained limited so far. Here, we present high-resolution cryo-electron microscopy (cryo-EM) structures of the Xanthomonas citri phage ΦXacJX1 from siphoviruses. These structures include atomic models for the head, head-to-tail connector and head-proximal portion of the tail. ΦXacJX1's head and head-to-tail connector components show significant protein sequence and structural homology with those of the model siphophage HK97. However, the in-situ structures of head-to-tail connector of phage HK97 remain unavailable. The presented structures of phage ΦXacJX1 enhance our understanding of Xanthomonas phages and the mature virion of phage HK97. They provide a valuable framework for future structural and functional studies on both Xanthomonas phages and phage HK97.