Molecular biology and structure of a novel penaeid shrimp densovirus elucidate convergent parvoviral host capsid evolution
Judit J. Pénzes, Hanh Thi Pham, Paul R. Chipman, Nilakshee Bhattacharya, Robert McKenna, Mavis Agbandje‐McKenna, Peter Tijssen
Abstract
Significance Parvoviruses (PVs) are ssDNA viruses, with T = 1 icosahedral symmetry, infecting deuterostome and protostome animals. Most PVs have a highly conserved phospholipase A2 domain (PLA2) in the N-terminal region of their minor capsid protein. Under acidic pH, during endosomal/lysosomal egress, the PLA2 domain is activated to disrupt vesicle membranes. However, certain PVs lack the PLA2 and thus must use a different escape mechanism. Our study offers insight into this enigma, showing how a recently discovered PV of marine crustacean has evolved a cation-dependent mechanism to accomplish this task. We also show how host-driven convergent evolution pushed two PVs, infecting the same host species, to adopt strikingly similar surface morphologies, despite distinct multimer interactions and lack of sequence similarity.