Polyamino acids that inhibit the interaction of yeast translational elongation factor-3 (EF-3) with ribosomes.
EF-3 is a translational elongation factor specific to yeasts and fungi. Its carboxy-terminal region contains three lysine-clusters and is very basic. The region has been reported to be responsible for the interaction with ribosomes [Ishiyama, A., Ogawa, K., & Miyazaki, M. (1992) in Abstracts of the 15th Annual Meeting of the Molecular Biology Society of Japan, p.190]. To find specific inhibitors for the interaction of EF-3 with ribosomes, the effects of two basic polyamino acids, poly-L-(Lys) and poly-L-(Arg), and two acidic polyamino acids, poly-L-(Asp) and poly-L-(Glu), were examined using two assay systems for ATPase of EF-3. One was for the ribosome-activated ATPase and the other for the intrinsic (ribosome-independent) ATPase of EF-3. Basic polyamino acids were expected to act as analogues of the carboxy-terminal region of EF-3, and acidic ones to interact with EF-3. The basic polyamino acids inhibited the ribosome-activated ATPase, but they also inhibited the intrinsic one more effectively. Acidic polyamino acids, poly-L-(Asp) and poly-L-(Glu), inhibited the ribosome-activated ATPase but not the intrinsic one. Thus, acidic polyamino acids could be specific inhibitors of the interaction between EF-3 and ribosomes. Furthermore, a system for detecting the binding of EF-3 to ribosomes was constructed. That is, ribosome-bound EF-3 was detected by measuring the ATPase on precipitated ribosomes after a mixture of EF-3 and ribosomes had been ultracentrifuged. Using this system, poly-L-(Asp) was shown to inhibit the binding of EF-3 to ribosomes directly.
Uritani
M
M
Department of Chemistry, Faculty of Science, Shizuoka University.
Nakano
K
K
Aoki
Y
Y
Shimada
H
H
Arisawa
M
M
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors; D005656:Fungal Proteins / Q000037:antagonists & inhibitors*; D010445:Peptide Elongation Factors / Q000037:antagonists & inhibitors*; D010455:Peptides / Q000494:pharmacology*; D011099:Polyglutamic Acid / Q000494:pharmacology; D011107:Polylysine / Q000494:pharmacology; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000187:drug effects* / Q000378:metabolism; D012440:Saccharomyces / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins
D005656:Fungal Proteins; D010445:Peptide Elongation Factors; D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; C111584:YEF3 protein, S cerevisiae; D011107:Polylysine; C015462:polyarginine; D011099:Polyglutamic Acid; C017645:polyaspartate; D000251:Adenosine Triphosphatases