Translation elongation factor 1P (EF-lP) catalyzes the exchange of bound GDP for GTP on EF-la. The lethality of a null allele of the TW5 gene encoding EF-lP in Saccharomyces cerevisiae was suppressed by extra copies of the TW2 gene encoding EF-la. The strains with tefs::TRPl suppressed by extra copies of TEF2 were slow growing, cold sensitive, hypersensitive to inhibitors of translation elongat...