Stimulation of <i>Escherichia Coli</i> elongation factor Tu‐dependent GTP hydrolysis by aminoacyl oligonucleotides in the presence of aurodox

Abstract

During protein synthesis in a ~rocaryotjc e&l, elongation factor Tu plays an important role by promoting the binding of AA-tRNA to ribosomes.This binding is mediated through the formation of a ternary complex of AA-tRNA .EF-Tu .GTP, followed by the hydrolysis of CTP during the binding of AA-tRNA to the ribosomal A site.The binary complex EF-Tu -GDP is then released from the ribosome and is recycled through the formation of transient EF-Tu -Ts complex.After the displacement of EF-Ts by GTP, the EF-Tu .GTP can interact with another molecule af AAtRNA [3],The antibiotic ~rromy~in (or its derivatives, e.g., Aurodox) inhibits protein biosynthesis by virtue of its interaction with EF-Tu and effects practically all the EF-Tu-dependent reactions, presumably through a conformati~nal alteration of EF-Tu [4,5].This antibiotic enables EF-Tu alone to catalyze the hydrolysis of GTP in the absence of other com~nents such as AA-tRNA and ribosomes which are otherwise required.Abbreviations: EF-Tu, elongation factor Tu; A-Phe, 2'(3')-O-L-phenylalanyladenosine; analogous abbreviations for other nucleoside and dinuc~eotjde derivatives; C-2'dA-2'-NN-~lu,cytidylyl(3'-5') 2'deoxy-2'~L-~utamyiam~doadenosine; C-3'dA-Lys, cytidyfyl(3'4') 3'-cleoxy-2'11-(L-ly?;ylfadenosine, analogous abbreviations for isomeric aminoacyi derivatives; Me, Cly, oammoisobutyric acid.AA-tRNA, aminoacy1 tRNA; AC-AA-tR~A,~-a~etyl aminoacyl tRNA, TPCK, L-I-tosyfamidoJ-phenylethyl chioromethyl ketone; PEP, phosphoenolpyrwvate; DTT, dithiothrietol, TLC, thin-layer ~hromat5~ap~yAurodox is the designation of antibiotic X-5108 and is N-methyiated kirramycin 111.It is identical to kirromycin in its effect on EF-Tu catalyzed GTP hydrolysis [2]