Zn binding SARS-CoV-2 orf7a and orf8 non-structural proteins XAS study

A promising way to develop therapeutic strategies against SARS-CoV-2 is to modulate the interactions of proteins coded in the viral genome with proteins expressed by the host organism. Within this framework, possible targets are the SARS-CoV-2 orf7a and orf8 non-structural proteins. The most supported hypothesis proposed for orf7a function is the interference with virion budding tethering operated by cellular antigens, while the function of orf8 is still unknown. In this proposal, we aim at studying the interaction of orf7a and orf8 with the tetherin protein known as bone marrow stromal antigen 2 (BST2). The mechanism of BST2 tethering involves BST2 dimerization and oligomerization, where oligomers are stabilized by intermolecular disulfide bonds formed between conserved cysteine residues. The BST2 dimerization process is strongly influenced by the presence of divalent cations, such as Zn(II), as they may interfere in disulfide Cys binding.