TY - JOUR
T1 - Transient idling of posttermination ribosomes ready to reinitiate protein synthesis
AU - Karamyshev, Andrey L.
AU - Karamysheva, Zemfira N.
AU - Yamami, Tohru
AU - Ito, Koichi
AU - Nakamura, Yoshikazu
N1 - Funding Information:
We thank Colin Crist for critical reading of the manuscript and valuable comments. This work was supported in part by grants from The Ministry of Education, Sports, Culture, Science and Technology of Japan (MEXT); the Organization for Pharmaceutical Safety and Research (OPSR); Russian Foundation for Basic Research; and support for Leading Russian Scientific Schools.
PY - 2004/12
Y1 - 2004/12
N2 - The fate of ribosomes between termination and initiation during protein synthesis is very basic, yet poorly understood. Here we found that translational reinitiation of the alkaline phosphatase gene occurs in Escherichia coli from an internal methionine codon when the authentic translation is prematurely terminated at a nonsense codon that is within seven codons upstream of the reinitiation codon (which we refer to as "reinitiation window"). Changing the reading frame downstream of the stop codon did not abolish the reinitiation, while inactivating the upstream initiation codon abolished the reinitiation. Moreover, depletion of the ribosome recycling factor (RRF), which disassembles posttermination ribosomes in conjunction with elongation factor G, did not influence the observed reinitiation. These findings suggest that posttermination ribosomes can undergo a transient idling state ready to reinitiate protein synthesis even in the absence of the Shine-Dalgarno (SD) sequence within the reinitiation window by evading disengagement from the mRNA.
AB - The fate of ribosomes between termination and initiation during protein synthesis is very basic, yet poorly understood. Here we found that translational reinitiation of the alkaline phosphatase gene occurs in Escherichia coli from an internal methionine codon when the authentic translation is prematurely terminated at a nonsense codon that is within seven codons upstream of the reinitiation codon (which we refer to as "reinitiation window"). Changing the reading frame downstream of the stop codon did not abolish the reinitiation, while inactivating the upstream initiation codon abolished the reinitiation. Moreover, depletion of the ribosome recycling factor (RRF), which disassembles posttermination ribosomes in conjunction with elongation factor G, did not influence the observed reinitiation. These findings suggest that posttermination ribosomes can undergo a transient idling state ready to reinitiate protein synthesis even in the absence of the Shine-Dalgarno (SD) sequence within the reinitiation window by evading disengagement from the mRNA.
KW - Protein synthesis
KW - Reinitiation
KW - Stop-codon
KW - Translation
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U2 - 10.1016/j.biochi.2004.08.006
DO - 10.1016/j.biochi.2004.08.006
M3 - Article
C2 - 15667944
AN - SCOPUS:12744253291
SN - 0300-9084
VL - 86
SP - 933
EP - 938
JO - Biochimie
JF - Biochimie
IS - 12
ER -