One SmpB molecule accompanies tmRNA during its passage through the ribosomes.
tmRNA and SmpB are the main participants of trans-translation, a process which rescues the ribosome blocked during translation of non-stop mRNA. While a one-to-one stoichiometry of tmRNA to the ribosome is generally accepted, the number of SmpB molecules in the complex is still under question. We have isolated tmRNA-ribosome complexes blocked at different steps of the tmRNA path through the ribosome and analyzed the stoichiometry of the complexes. Ribosome, tmRNA and SmpB were found in equimolar amount in the tmRNA-ribosome complexes stopped at the position of the 2nd, 4th, 5th or the 11th codons of the coding part of the tmRNA.
Bugaeva
Elizaveta Y
EY
Belozersky Institute, Build. A, Moscow State University, Moscow 119992, Russia.
Shpanchenko
Olga V
OV
Felden
Brice
B
Isaksson
Leif A
LA
Dontsova
Olga A
OA
D000595:Amino Acid Sequence; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D016601:RNA-Binding Proteins; C430328:small protein B; C096222:tmRNA