期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：8
页码：2224-2228
DOI：10.1073/pnas.70.8.2224
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：50S-derived cores were prepared by treatment of 50S subunits with 0.4 M Licl (0.4c core) and 0.8 M Licl (0.8c core), respectively. 0.4c cores bind chloramphenicol whereas 0.8c cores do not. The split proteins obtained during the transitions 0.4c [->] 0.8c were separated by DEAE-cellulose chromatography and Sephadex G-100 gel filtration. Reconstitution experiments with the fractionated proteins demonstrated that protein L16 is involved in chloramphenicol binding. In contrast to chloramphenicol, the CACCA-(N-acetyl-leucyl) fragment is bound by the 0.8c core, i.e., this core contains the intact p-site moiety of the peptidyltransferase center. Puromycin can inhibit chloramphenicol binding completely. In the concentration range tested (up to 20 mM) the trinucleotide CCA inhibits chloramphenicol binding as effectively as puromycin, whereas an aminoacid mixture shows no inhibition. It is concluded that chloramphenicol acts exclusively on the a-site part of the peptidyltransferase center interfering with the binding of the last two or three nucleotides (3' end) of aminoacyl-tRNA.
