• Human SARSr-CoV Spike protein is highly conserved in both S1 and S2 subunits. • The S1-RBD, -SD1; S2-CR, -HR1 and -CH are the most promising druggable S regions. • 28 main consensus druggable pockets were found with high druggabbility score. • New hot spots were identified for hSARSr-CoVs (n = 181) and Beta-CoVs (n = 72). • A structure-based rationale is disclosed for drug design and discovery.

Influenza and COVID-19 are infectious respiratory diseases that represent a major concern to public health with social and economic impact worldwide, for which the available therapeutic options are not satisfactory. The RdRp has a central role in viral replication and thus represents a major target for the development of antiviral approaches. In this study, we focused on Influenza A virus PB1 polymerase protein and the betacoronaviruses nsp12 polymerase protein, considering their functional and structural similarities. We have performed conservation and druggability analysis to map conserved druggable regions, that may have functional or structural importance in these proteins. We disclosed the most promising and new targeting regions for the discovery of new potential polymerase inhibitors. Conserved druggable regions of putative interaction with favipiravir and molnupiravir were also mapped. We have also compared and integrated the current findings with previous research.

Non-structural protein 1 (NS1) of influenza A virus is a multifunctional virulence factor and represents a promising anti-influenza target, considering its conserved and druggable structure. As antiviral target, NS1-RNA-binding domain (RBD) remains unexplored, despite its critical role in replication. In this study, we applied a “Map-and-Mutate” strategy to identify and functionally validate highly conserved and druggable regions within the NS1-RBD. Using large-scale sequence alignments and structural characterization, we integrated conservation and druggability analyses to predict conserved druggable pockets and top-ranked hot spots, mutate the five most promising residues (L15, W16, R19, R35, and L43) and study their impact on viral fitness. In vitro, the mutations W16 and R35 caused most significant reduction in viral fitness; however, L15 and R19 also impaired replication. Combined mutations involving W16 and either L15 or L43 exerted a cumulative effect, reducing viral replication, hemagglutination titers and neuraminidase activity. This study demonstrates that most residues identified and investigated using the “Map-and-Mutate” strategy negatively impact viral fitness, underscoring the approach’s value in pinpointing novel antiviral targets. Together with our prior research, this study reinforces the importance of NS1 as a promising antiviral target, providing a rationale for designing and developing therapies with a higher resilience to viral resistance.