An archaeal virus capable of hydrolyzing the surface glycan of the host cell

Spindle-shaped viruses exclusively infect archaea. Fuselloviruses represent a large group of spindle-shaped viruses and infect hyperthermophilic archaea of the order Sulfolobales. Although the first fusellovirus was identified nearly 40 years ago, the mechanism of host infection by these viruses remains poorly understood. Here, we show that SSV19, a fusellovirus isolated from a hot spring in the Philippines, is capable of hydrolyzing the host cell surface glycan identified as a heptasaccharide chain of QuiS₁Hex₄HexNAc₂. Our findings provide significant insights into the molecular strategy of host recognition and, possibly, entry by an archaeal virus.