Molecular architecture of 40S initiation complexes on the Hepatitis C virus IRES: from ribosomal attachment to eIF5B-mediated reorientation of initiator tRNA

Brown, Zuben P.; Abaeva, Irina S; De, Swastik; Hellen, Christopher U.T.; Pestova, Tatyana V.; Frank, Joachim

doi:10.1101/2021.12.10.472117

“…Interactions between human eIF5B and eIF1A contributing to an adequate positioning of the initiator tRNA on the SSU were also observed in two eukaryotic studies published in BioRxiv ( 54 , 55 ) while this manuscript was being written. These interactions involve the two terminal α-helices of eIF5B and the β2-β3 loop of eIF1A and contribute to a relatively small interaction surface (∼150 Å 2 ).…”

Section: Discussionsupporting

confidence: 54%

“…While writing our results, two manuscripts describing mammalian complexes containing the 40S subunit, eIF5B and eIF1A were deposited in BioRxiv ( 54 , 55 ). Our data will also be discussed in the light of these recent results.…”

Section: Introductionmentioning

confidence: 99%

Role of aIF5B in archaeal translation initiation

Kazan

¹

,

Bourgeois

²

,

Lazennec‐Schurdevin

³

et al. 2022

Nucleic Acids Research

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In eukaryotes and in archaea late steps of translation initiation involve the two initiation factors e/aIF5B and e/aIF1A. In eukaryotes, the role of eIF5B in ribosomal subunit joining is established and structural data showing eIF5B bound to the full ribosome were obtained. To achieve its function, eIF5B collaborates with eIF1A. However, structural data illustrating how these two factors interact on the small ribosomal subunit have long been awaited. The role of the archaeal counterparts, aIF5B and aIF1A, remains to be extensively addressed. Here, we study the late steps of Pyrococcus abyssi translation initiation. Using in vitro reconstituted initiation complexes and light scattering, we show that aIF5B bound to GTP accelerates subunit joining without the need for GTP hydrolysis. We report the crystallographic structures of aIF5B bound to GDP and GTP and analyze domain movements associated to these two nucleotide states. Finally, we present the cryo-EM structure of an initiation complex containing 30S bound to mRNA, Met-tRNAiMet, aIF5B and aIF1A at 2.7 Å resolution. Structural data shows how archaeal 5B and 1A factors cooperate to induce a conformation of the initiator tRNA favorable to subunit joining. Archaeal and eukaryotic features of late steps of translation initiation are discussed.

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“…Interactions between human eIF5B and eIF1A contributing to an adequate positioning of the initiator tRNA on the SSU were also observed in two eukaryotic studies published in BioRxiv (53,54) while this manuscript was being written. These interactions involve the two terminal α-helices of eIF5B and the 2-3 loop of eIF1A and contribute to a relatively small interaction surface (∼150 Å 2 ).…”

Section: Discussionsupporting

confidence: 54%

“…While writing our results, two manuscripts describing mammalian complexes containing the 40S subunit, eIF5B and eIF1A were deposited in BioRxiv (53,54). Our data will also be discussed at the light of these recent results.…”

Section: Introductionmentioning

confidence: 99%

Role of aIF5B in archaeal translation initiation

Kazan

¹

,

Bourgeois

²

,

Lazennec‐Schurdevin

³

et al. 2022

Preprint

1

0

View full text Add to dashboard Cite

In eukaryotes and in archaea late steps of translation initiation involve the two initiation factors e/aIF5B and e/aIF1A. In eukaryotes, the role of eIF5B in ribosomal subunit joining is established and structural data showing eIF5B bound to the full ribosome were obtained. To achieve its function, eIF5B collaborates with eIF1A. However, structural data illustrating how these two factors interact on the small ribosomal subunit have long been awaited. The role of the archaeal counterparts, aIF5B and aIF1A, remains to be extensively addressed. Here, we study the late steps of Pyrococcus abyssi translation initiation. Using in vitro reconstituted initiation complexes and light scattering, we show that aIF5B bound to GTP accelerates subunit joining without the need for GTP hydrolysis. We report the crystallographic structures of aIF5B bound to GDP and GTP and analyze domain movements associated to these two nucleotide states. Finally, we present the cryo-EM structure of an initiation complex containing 30S bound to mRNA, Met-tRNAiMet, aIF5B and aIF1A at 2.7 Å resolution. Structural data shows how archaeal 5B and 1A factors cooperate to induce a conformation of the initiator tRNA favorable to subunit joining. Archaeal and eukaryotic features of late steps of translation initiation are discussed.

show abstract

“…Interactions between human eIF5B and eIF1A contributing to an adequate positioning of the initiator tRNA on the SSU were also observed in two eukaryotic studies published in BioRxiv (54,55) while this manuscript was being written. These interactions involve the two terminal ␣helices of eIF5B and the ␤2-␤3 loop of eIF1A and contribute to a relatively small interaction surface (∼150 Å2 ).…”

Section: Discussionmentioning

confidence: 52%

Role of aIF5B in archaeal translation initiation

Kazan¹,

Bourgeois²,

Lazennec‐Schurdevin³

et al. 2022

Acta Cryst Sect A

0

View full text Add to dashboard Cite

In eukaryotes and in archaea late steps of translation initiation involve the two initiation factors e/aIF5B and e/aIF1A. In eukaryotes, the role of eIF5B in ribosomal subunit joining is established and structural data showing eIF5B bound to the full ribosome were obtained. To achieve its function, eIF5B collaborates with eIF1A. However, structural data illustrating how these two factors interact on the small ribosomal subunit have long been awaited. The role of the archaeal counterparts, aIF5B and aIF1A, remains to be extensively addressed. Here, we study the late steps of Pyrococcus abyssi translation initiation. Using in vitro reconstituted initiation complexes and light scattering, we show that aIF5B bound to GTP accelerates subunit joining without the need for GTP hydrolysis. We report the crystallographic structures of aIF5B bound to GDP and GTP and analyze domain movements associated to these two nucleotide states. Finally, we present the cryo-EM structure of an initiation complex containing 30S bound to mRNA, Met-tRNA i Met , aIF5B and aIF1A at 2.7 Å resolution. Structural data shows how archaeal 5B and 1A factors cooperate to induce a conformation of the initiator tRNA favorable to subunit joining. Archaeal and eukaryotic features of late steps of translation initiation are discussed.

show abstract

Molecular architecture of 40S initiation complexes on the Hepatitis C virus IRES: from ribosomal attachment to eIF5B-mediated reorientation of initiator tRNA

Cited by 4 publications

References 87 publications

Role of aIF5B in archaeal translation initiation

Role of aIF5B in archaeal translation initiation

Role of aIF5B in archaeal translation initiation

Role of aIF5B in archaeal translation initiation

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