Pseudokinase that plays a role in viral DNA replication repression by activating the antiviral protein BANF1 and inhibiting the activity of host VRK1, a cellular modulator of BANF1. Both catalytically active kinases B1/VPK1 and host VRK2 repress B12 inhibitory activity in a B1/VPK1 deletion mutant strain. Interacts with B1/VPK1 (PubMed:31341052). Interacts with host VRK1 (PubMed:33177193). Interacts with host VRK2 (PubMed:31341052, PubMed:33177193). Expressed in the early phase of the viral replicative cycle. Deletion mutants exhibit rescued DNA replication and viral yield in multiple cell lines when B1 kinase/VPK1 is deleted. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. Poxviruses subfamily.