sentence: Briefly , cells lacking ASI1 , ASI2 , ASI3 , HRD1 and DOA10 were transformed with high copy plasmids from the pRS42X series ( Mumberg et al ., 1994 ) encoding untagged Asi1 and Asi3 as well as Asi2 fused to a N-terminal SBP ( Streptavidin binding peptide ) ( Keefe et al ., 2001 ) followed by a TEV protease cleavage site .