To fit all of your expression needs, Invitrogen offers state-of-the-art Gateway® destination vectors for expression in E. coli, insect, yeast, or mammalian cells, as well as for production of native protein or N- or C-terminal fusion proteins. All Gateway® destination vectors have attR sites for recombination with any attL-flanked fragment, regardless of whether it is an entry clone or an Ultimate? RF Clone. The following table lists the wide range of destination vectors available.