Flexibility of the MultiSite Gateway™ cloning system. The flexibility of the MultiSite GatewayTM system is illustrated by the ample possibilities to combine any gene of interest (GOI) with any promoter of interest (POI) and tag of interest (TOI), depending on the experimental needs. Many of such sequences, including whole ORFeomes (cloned without STOP codon) of several model organisms [16–19] and a broad range of tags [5, 9–11] are already available in suitable pDONR vectors. L1-L4 and R1-R2 stand for the att sites attL1 attL4 and attR1 attR2, respectively. Asterisks mark constructs generated in this study, lower case letters indicate constructs generated previously by others: a , b , c , d , e , f , g ,h .