The crystal structure of novel chondroitin lyase ODV-E66, a baculovirus envelope protein

• The crystal structures of a novel chondroitin lyase from baculovirus was determined.
• The structural fold of ODV-E66 resembled that of PL8 family enzymes.
• The catalytic residues were conserved between ODV-E66 and PL8 family enzymes.

Chondroitin lyases have been known as pathogenic bacterial enzymes that degrade chondroitin. Recently, baculovirus envelope protein ODV-E66 was identified as the first reported viral chondroitin lyase. ODV-E66 has low sequence identity with bacterial lyases at <12%, and unique characteristics reflecting the life cycle of baculovirus. To understand ODV-E66’s structural basis, the crystal structure was determined and it was found that the structural fold resembled that of polysaccharide lyase 8 proteins and that the catalytic residues were also conserved. This structure enabled discussion of the unique substrate specificity and the stability of ODV-E66 as well as the host specificity of baculovirus.