Crystallization of alpha and beta subunits of IF2 translation initiation factor from archaebacteria Sulfolobus solfataricus

2008 ◽  
Vol 310 (16) ◽  
pp. 3767-3770 ◽  
Author(s):  
E. Pechkova ◽  
F. Vasile ◽  
R. Spera ◽  
C. Nicolini
Keyword(s):  
Translation Initiation ◽  
Sulfolobus Solfataricus ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Beta Subunits

Conformational transitions in the γ subunit of the archaeal translation initiation factor 2

2014 ◽  
Vol 70 (3) ◽  
pp. 658-667 ◽  
Author(s):  
Oleg Nikonov ◽  
Elena Stolboushkina ◽  
Valentina Arkhipova ◽  
Olesya Kravchenko ◽  
Stanislav Nikonov ◽  
...  
Keyword(s):  
Translation Initiation ◽  
Inorganic Phosphate ◽  
Bound States ◽  
Sulfolobus Solfataricus ◽  
Conformational Transitions ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Γ Subunit ◽  
Initiation Factor 2 ◽  
Translation Initiation Factor 2

In eukaryotes and archaea, the heterotrimeric translation initiation factor 2 (e/aIF2) is pivotal for the delivery of methionylated initiator tRNA (Met-tRNAi) to the ribosome. It acts as a molecular switch that cycles between inactive (GDP-bound) and active (GTP-bound) states. Recent studies show that eIF2 can also exist in a long-lived eIF2γ–GDP–Pi(inorganic phosphate) active state. Here, four high-resolution crystal structures of aIF2γ fromSulfolobus solfataricusare reported: aIF2γ–GDPCP (a nonhydrolyzable GTP analogue), aIF2γ–GDP–formate (in which a formate ion possibly mimics Pi), aIF2γ–GDP and nucleotide-free aIF2γ. The structures describe the different states of aIF2γ and demonstrate the conformational transitions that take place in the aIF2γ `life cycle'.

Binding of the 5′-Triphosphate End of mRNA to the γ-Subunit of Translation Initiation Factor 2 of the Crenarchaeon Sulfolobus solfataricus

2015 ◽  
Vol 427 (19) ◽  
pp. 3086-3095 ◽  
Author(s):  
Valentina Arkhipova ◽  
Elena Stolboushkina ◽  
Olesya Kravchenko ◽  
Vladislav Kljashtorny ◽  
Azat Gabdulkhakov ◽  
...  
Keyword(s):  
Translation Initiation ◽  
Sulfolobus Solfataricus ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Γ Subunit ◽  
Initiation Factor 2 ◽  
Translation Initiation Factor 2

scholarly journals Back to translation: removal of aIF2 from the 5′-end of mRNAs by translation recovery factor in the crenarchaeon Sulfolobus solfataricus

2013 ◽  
Vol 42 (4) ◽  
pp. 2505-2511 ◽  
Author(s):  
Birgit Märtens ◽  
Salim Manoharadas ◽  
David Hasenöhrl ◽  
Lukas Zeichen ◽  
Udo Bläsi
Keyword(s):  
Stationary Phase ◽  
Translation Initiation ◽  
Sulfolobus Solfataricus ◽  
Growth Conditions ◽  
Translation Initiation Factor ◽  
Recovery Factor ◽  
Initiation Factor ◽  
Ribosome Binding ◽  
Γ Subunit

Abstract The translation initiation factor aIF2 of the crenarchaeon Sulfolobus solfataricus (Sso) recruits initiator tRNA to the ribosome and stabilizes mRNAs by binding via the γ-subunit to their 5′-triphosphate end. It has been hypothesized that the latter occurs predominantly during unfavorable growth conditions, and that aIF2 or aIF2-γ is released on relief of nutrient stress to enable in particular anew translation of leaderless mRNAs. As leaderless mRNAs are prevalent in Sso and aIF2-γ bound to the 5′-end of a leaderless RNA inhibited ribosome binding in vitro, we aimed at elucidating the mechanism underlying aIF2/aIF2-γ recycling from mRNAs. We have identified a protein termed Trf (translation recovery factor) that co-purified with trimeric aIF2 during outgrowth of cells from prolonged stationary phase. Subsequent in vitro studies revealed that Trf triggers the release of trimeric aIF2 from RNA, and that Trf directly interacts with the aIF2-γ subunit. The importance of Trf is further underscored by an impaired protein synthesis during outgrowth from stationary phase in a Sso trf deletion mutant.

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