Saccharomyces cerevisiae strain BY4741 (MATa his3D1 leu2D0 met15D0 ura3D0) and the single-gene deletion strain of the TEF4-encoded form of eEF1Bc (tef4D) were obtained from Open Biosystems (Huntville, AL). TKY680 strain in which both yeast encoded eEF1Bc, TEF4 and TEF3 were deleted (MATa ura3-52 leu2D1 his3D200 trp1D101 lys2-801 tef3::LEU2 tef4::TRP1) and its isogenic wild type TKY677 (MATa ura3-52 leu2D1 his3D200 trp1D101 lys2-801) as well as the isogenic single deletion mutant strains, TKY678 (MATa ura3-52 leu2D1 his3D200 trp1D101 lys2-801 tef3::LEU2) and TKY 679 (MATa ura3-52 leu2D1 his3D200 trp1D101 lys2-801 tef4::TRP1) were published previously [30] . The following plasmids pESC-GAL1-Hisp33/GAL10-DI-72, pGAD-CUP1-p92 pYES-GAL1-p92, pCM189-TET-His92 were described earlier [21, 22] . URA3 based pGBK-ADH-Hisp33/ GAL1-DI72, pGBK-CUP1-HisFLAGp33/GAL1-DI-72, and pGBK-CUP1-Hisp33/GAL1-DI-72 plasmids were constructed by Daniel Barajas (unpublished result). The URA3 based, low copy-number plasmid, pYC-GAL1-Tef4 expressing non-tagged full-length Tef4 protein was constructed as follows: pYC/NT-C plasmid was digested with BamHI and XhoI restriction enzymes and then PCR product of the TEF4 gene was generated with primers #2089 (ccgcGGATCCATGTCCCAAGGTACTTTA-TAC) and #2320 (CGCCTCGAGTTATTTCAAAACCT-TACCGTCAACAATTTCC) and digested with the same restriction enzymes, followed by ligation. The plasmid pYES-NTC2-GAL1-HisTef4 expressing His 6 -tagged Tef4p protein was created with the same restriction enzymes using pYES-NT-C2.