Stimulatory effect of UTP on peptide chain initiation in Streptomyces aureofaciens

The formation of the 30S and 70S initiation complex in Streptomyces aureofaciens differs from that in E.coli and B.stearothermophilus with respect to the requirement for nucleotide triphosphates for the maximum activity. In the presence of GTP and initiation factors from S.aureofaciens the codon specific binding of fMet-tRNA to ribosomes of S.aureofaciens was stimulated by ATP or UTP. UTP exhibited the most significant effect increasing the binding about 3.5 times, whereas CTP had no effect on the reaction. The stimulatory effect of UTP is GTP-dependent and was not observed in experiments with E.coli ribosomes.