[Characteristics of nonenzymatic binding of oligoribonucleotides-- analogs of mRNA and Phe-tRNA Phe with 80S ribosomes from human placenta].
Binding of labelled oligouridylates--mRNA analogs--to human placenta 80S ribosomes in the presence of Phe-tRNAPhe has been studied. The single site for (pU)n (n = 6, 9, 13) binding on the ribosome was found; association constants for their tRNA-dependent binding were evaluated. In the presence of oligouridylates as templates [14C]Phe-tRNAPhe was found to be able to bind simultaneously at acceptor and donor ribosomal sites which resulted in diphenylalanine formation. The observed maximum Phe-tRNAPhe binding level was considerably lower than for the corresponding oligouridylate binding; the longer oligouridylate the higher Phe-tRNAPhe maximum binding level. To explain the results obtained we have proposed that (i) (Phe)2-tRNA produced from transpeptidation dissociates from the ribosomal A site to a significant extent and (ii) when oligouridylate length increases its interaction with 3'-side of mRNA binding center results in allosteric stabilization of the complex of peptidyl-tRNA with the ribosome at A site.
Graĭfer
D M
DM
Zenkova
M A
MA
Karpova
G G
GG
Malygin
A A
AA
Matasova
N B
NB
D001665:Binding Sites; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D009843:Oligoribonucleotides / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011072:Poly U / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012360:RNA, Transfer, Phe / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D014500:Uracil Nucleotides / Q000378:metabolism*
D009843:Oligoribonucleotides; D012333:RNA, Messenger; D012360:RNA, Transfer, Phe; D014500:Uracil Nucleotides; C027916:oligo(U); D011072:Poly U
Osobennosti neénzimaticheskogo sviazyvaniia oligoribonukleotidov-- analogov mRNK i Phe-tRNK Phe s 80S ribosomami iz platsenty cheloveka.