Apoptosis is a crucial immune response and can be triggered to prevent virus proliferation. Therefore, many viruses developed tools to thwart the cell death. Among these viruses, some poxviruses have been demonstrated to encode Bcl-2-like proteins that interact with cellular pro-apoptotic Bcl-2 and stop the apoptosis intrinsic pathway.
Genomic studies revealed the possibility of such a protein expressed by the deer pox virus: DPV022.
Despite lacking detectable sequence identity with mammalian Bcl-2 proteins, DPV022 is able to prevent growth arrest by Bak and Bax in yeast. Next we quantified the interaction between DPV022 and human Bcl-2 family members. Based on these data we crystallized and solved the structure of DPV022 with Bim. This structure unexpectedly revealed a domain-swapped dimer topology first identified in vaccinia virus Bcl-2 proteins, and suggests there may be a define class of Bcl-2 proteins that adopt this quaternary structure.