sentence: Cleaved PLV migrates to the nucleus and activates HIS3 , which allows growth in the absence of histidine , and LacZ encoding beta-galactosidase which leads to blue colouring of cells growing on X-gal.A different variant of the split-ubiquitin system has been used to demonstrate interactions of translocon components , but neither Sec61p nor Ssh1p were used as baits [ 6,12 ] .