We focus on virus structures, virus-cell attachment, endocytic uptake of virus particles, fusion between viral and host membranes, and the mechanism of genome release. To this end, we developed novel systems for the expression of recombinant viral attachment/ fusion proteins, which are applied to study the interaction of viruses with their receptors. Our multidisciplinary approach entails molecular virology (reverse and forward genetics), structural biology (crystallography, EM), glycobiology (e.g. glycan array analysis), biophysics, biochemistry, cell biology (e.g siRNA screens and haploid cell screens), bio-informatics, and in vivo studies.