[Spatial proximity of the ribosomal mRNA binding center to the 50S subunit].
4-(N-2-chloroethyl-N-methylamino)benzylamide of 5'-heptaadenylic acid was used for affinity labelling of the ribosome in the vicinity of its mRNA-binding centre. This derivative, similar to the free oligonucleotide, stimulates the binding of [14C]-lysyl-tRNA to ribosomes of E. coli and alkylates ribosomes both the 30S and the 50S subunits. The alkylation of ribosomes is inhibited by pre-incubation of ribosomes with polyadenylic acid, which suggests that the chemical modification is a specific one and occurs in the vicinity of mRNA-binding site. The fact, that a short oligonucleotide having an active group on its 5'end attacks the 50S subunit of ribosome may indicate that the mRNA-binding centre is located in the contact region between ribosomal subunits.
D000345:Affinity Labels; D001665:Binding Sites; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004926:Escherichia coli / Q000648:ultrastructure*; D012333:RNA, Messenger; D012270:Ribosomes
D000345:Affinity Labels; D012333:RNA, Messenger
Prostranstvennaia blizost' mRNK-sviazyvaiushchego tsentra ribosomy k 50S-sub''edinitse.