TY - JOUR
T1 - A gating mechanism for Pi release governs the mRNA unwinding by eIF4AI during translation initiation
AU - Lu, Junyan
AU - Jiang, Chenxiao
AU - Li, Xiaojing
AU - Jiang, Lizhi
AU - Li, Zengxia
AU - Schneider-Poetsch, Tilman
AU - Liu, Jianwei
AU - Yu, Kunqian
AU - Liu, Jun O.
AU - Jiang, Hualiang
AU - Luo, Cheng
AU - Dang, Yongjun
N1 - Funding Information:
Ministry of Science and Technology of China [2015CB910304 to H.J.]; Hi-Tech Research and Development Program of China [2012AA020301 to K.Y., 2012AA01A305 to H.J. and 2012AA020302 to C.L.]; National Natural Science Foundation of China [81430084 and 21472208 to C.L., 31270830 and 21572038 to Y.D.]; Fund of State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences [to Y.D.]; Startup Fund at Fudan University [to Y.D.]; Fund of State Key Laboratory of Toxicology and Medical Countermeasures, Academy of Military Medical Science [TMC201505 to C.L.]. Funding for open access charge: The National Natural Science Foundation of China [81430084 and 21472208 to C.L., 31270830 and 21572038 to Y.D.]. Conflict of interest statement. None declared.
Funding Information:
The authors acknowledge support from Computer Network Information Center, Chinese Academy of Sciences, Tianjin and Shanghai Supercomputing Center.
Funding Information:
Ministry of Science and Technology of China [2015CB910304 to H.J.]; Hi-Tech Research and Development Program of China [2012AA020301 to K.Y., 2012AA01A305 to H.J. and 2012AA020302 to C.L.]; National Natural Science Foundation of China [81430084 and 21472208 to C.L., 31270830 and 21572038 to Y.D.]; Fund of State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences [to Y.D.]; Startup Fund at Fudan University [to Y.D.]; Fund of State Key Laboratory of Toxicology and Medical Countermeasures, Academy of Military Medical Science [TMC201505 to C.L.]. Grant: for open access charge: The National Natural Science Foundation of China [81430084 and 21472208 to C.L., 31270830 and 21572038 to Y.D.].
Publisher Copyright:
© The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.
PY - 2015
Y1 - 2015
N2 - Eukaryotic translation initiation factor eIF4AI, the founding member of DEAD-box helicases, undergoes ATP hydrolysis-coupled conformational changes to unwind mRNA secondary structures during translation initiation. However, the mechanism of its coupled enzymatic activities remains unclear. Here we report that a gating mechanism for Pi release controlled by the inter-domain linker of eIF4AI regulates the coupling between ATP hydrolysis and RNA unwinding. Molecular dynamic simulations and experimental results revealed that, through forming a hydrophobic core with the conserved SAT motif of the N-terminal domain and I357 from the C-terminal domain, the linker gated the release of Pi from the hydrolysis site, which avoided futile hydrolysis cycles of eIF4AI. Further mutagenesis studies suggested this linker also plays an auto-inhibitory role in the enzymatic activity of eIF4AI, which may be essential for its function during translation initiation. Overall, our results reveal a novel regulatory mechanism that controls eIF4AI-mediated mRNA unwinding and can guide further mechanistic studies on other DEADbox helicases.
AB - Eukaryotic translation initiation factor eIF4AI, the founding member of DEAD-box helicases, undergoes ATP hydrolysis-coupled conformational changes to unwind mRNA secondary structures during translation initiation. However, the mechanism of its coupled enzymatic activities remains unclear. Here we report that a gating mechanism for Pi release controlled by the inter-domain linker of eIF4AI regulates the coupling between ATP hydrolysis and RNA unwinding. Molecular dynamic simulations and experimental results revealed that, through forming a hydrophobic core with the conserved SAT motif of the N-terminal domain and I357 from the C-terminal domain, the linker gated the release of Pi from the hydrolysis site, which avoided futile hydrolysis cycles of eIF4AI. Further mutagenesis studies suggested this linker also plays an auto-inhibitory role in the enzymatic activity of eIF4AI, which may be essential for its function during translation initiation. Overall, our results reveal a novel regulatory mechanism that controls eIF4AI-mediated mRNA unwinding and can guide further mechanistic studies on other DEADbox helicases.
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U2 - 10.1093/nar/gkv1033
DO - 10.1093/nar/gkv1033
M3 - Article
C2 - 26464436
AN - SCOPUS:84983752568
SN - 0305-1048
VL - 43
SP - 10157
EP - 10167
JO - Nucleic acids research
JF - Nucleic acids research
IS - 21
ER -