scholarly journals Crystal structure of the ATPase domain of translation initiation factor 4A from Saccharomyces cerevisiae – the prototype of the DEAD box protein family

Structure ◽  
1999 ◽  
Vol 7 (6) ◽  
pp. 671-679 ◽  
Author(s):  
Jörg Benz ◽  
Hans Trachsel ◽  
Ulrich Baumann
Keyword(s):  
Crystal Structure ◽  
Saccharomyces Cerevisiae ◽  
Translation Initiation ◽  
Protein Family ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Atpase Domain ◽  
Dead Box ◽  
The Dead

scholarly journals Fal1p is an essential DEAD-box protein involved in 40S-ribosomal-subunit biogenesis in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (12) ◽  
pp. 7283-7294 ◽  
Author(s):  
D Kressler ◽  
J de la Cruz ◽  
M Rojo ◽  
P Linder
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Translation Initiation ◽  
18S Rrna ◽  
Amino Acid Level ◽  
Ribosomal Subunit ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Northern Hybridization ◽  
Ribosomal Subunits ◽  
Dead Box

A previously uncharacterized Saccharomyces cerevisiae gene, FAL1, was found by sequence comparison as a homolog of the eukaryotic translation initiation factor 4A (eIF4A). Fal1p has 55% identity and 73% similarity on the amino acid level to yeast eIF4A, the prototype of ATP-dependent RNA helicases of the DEAD-box protein family. Although clearly grouped in the eIF4A subfamily, the essential Fal1p displays a different subcellular function and localization. An HA epitope-tagged Fal1p is localized predominantly in the nucleolus. Polysome analyses in a temperature-sensitive fal1-1 mutant and a Fal1p-depleted strain reveal a decrease in the number of 40S ribosomal subunits. Furthermore, these strains are hypersensitive to the aminoglycoside antibiotics paromomycin and neomycin. Pulse-chase labeling of pre-rRNA and steady-state-level analysis of pre-rRNAs and mature rRNAs by Northern hybridization and primer extension in the Fal1p-depleted strain show that Fal1p is required for pre-rRNA processing at sites A0, A1, and A2. Consequently, depletion of Fal1p leads to decreased 18S rRNA levels and to an overall deficit in 40S ribosomal subunits. Together, these results implicate Fal1p in the 18S rRNA maturation pathway rather than in translation initiation.

scholarly journals PRH75, a new nucleus-localized member of the DEAD-box protein family from higher plants.

1997 ◽  
Vol 17 (4) ◽  
pp. 2257-2265 ◽  
Author(s):  
Z J Lorković ◽  
R G Herrmann ◽  
R Oelmüller
Keyword(s):  
Amino Acids ◽  
Rna Binding ◽  
Protein Family ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Rna Helicases ◽  
Nuclear Targeting ◽  
Dead Box ◽  
Cell Extracts ◽  
The Dead

The putative RNA helicases of the DEAD-box protein family are involved in pre-mRNA splicing, rRNA maturation, ribosome assembly, and translation. Members of this protein family have been identified in organisms from Escherichia coli to humans, but except for the translation initiation factor 4A, there have been no reports on the characterization of other DEAD-box proteins from plants. Here we report on a novel member of the DEAD-box protein family, the plant RNA helicase 75 (PRH75). PRH75 is localized in the nucleus and contains two domains for RNA binding. One is located at the C terminus and is similar to RGG RNA-binding domains of nucleus-localized RNA-binding proteins. The other one is located between amino acids 308 and 622, a region containing the conserved motif VI characteristic of DEAD-box proteins and known as the RNA-binding site of eIF-4A. The N-terminal 81 amino acids are sufficient for nuclear targeting of the protein. Northern and Western blot analyses show that PRH75 is mainly expressed in young and rapidly developing tissues. The purified recombinant PRH75 has a weak ATPase activity which is barely stimulated by RNA ligands. The fractionation of spinach whole-cell extracts by glycerol gradient centrifugation and gel filtration on a Superdex 200 column shows that the protein exists in a complex of about 500 kDa. Possible biological functions of PRH75 as well as structure-function relationships in the context of its modular primary structure are discussed.

scholarly journals Translation initiation factor 4A from Saccharomyces cerevisiae: analysis of residues conserved in the D-E-A-D family of RNA helicases.

1991 ◽  
Vol 11 (7) ◽  
pp. 3463-3471 ◽  
Author(s):  
S R Schmid ◽  
P Linder
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Translation Initiation ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Clear Correlation ◽  
Temperature Sensitive ◽  
Rna Helicases ◽  
Initiation Of Translation

The eukaryotic translation initiation factor 4A (eIF-4A) possesses an in vitro helicase activity that allows the unwinding of double-stranded RNA. This activity is dependent on ATP hydrolysis and the presence of another translation initiation factor, eIF-4B. These two initiation factors are thought to unwind mRNA secondary structures in preparation for ribosome binding and initiation of translation. To further characterize the function of eIF-4A in cellular translation and its interaction with other elements of the translation machinery, we have isolated mutations in the TIF1 and TIF2 genes encoding eIF-4A in Saccharomyces cerevisiae. We show that three highly conserved domains of the D-E-A-D protein family, encoding eIF-4A and other RNA helicases, are essential for protein function. Only in rare cases could we make a conservative substitution without affecting cell growth. The mutants show a clear correlation between their growth and in vivo translation rates. One mutation that results in a temperature-sensitive phenotype reveals an immediate decrease in translation activity following a shift to the nonpermissive temperature. These in vivo results confirm previous in vitro data demonstrating an absolute dependence of translation on the TIF1 and TIF2 gene products.

scholarly journals Crystal structure of the MIF4G domain of the Trypanosoma cruzi translation initiation factor EIF4G5

2019 ◽  
Vol 75 (12) ◽  
pp. 738-743
Author(s):  
Lucca Pietro Camillo dos Santos ◽  
Bruno Moisés de Matos ◽  
Brenda Cecilia de Maman Ribeiro ◽  
Nilson Ivo Tonin Zanchin ◽  
Beatriz Gomes Guimarães
Keyword(s):  
Crystal Structure ◽  
Translation Initiation ◽  
Specific Interaction ◽  
Three Dimensional ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Dimensional Structure ◽  
Initiation Factors ◽  
Genes Encoding ◽  
Rna Complexes

Kinetoplastida, a class of early-diverging eukaryotes that includes pathogenic Trypanosoma and Leishmania species, display key differences in their translation machinery compared with multicellular eukaryotes. One of these differences involves a larger number of genes encoding eIF4E and eIF4G homologs and the interaction pattern between the translation initiation factors. eIF4G is a scaffold protein which interacts with the mRNA cap-binding factor eIF4E, the poly(A)-binding protein, the RNA helicase eIF4A and the eIF3 complex. It contains the so-called middle domain of eIF4G (MIF4G), a multipurpose adaptor involved in different protein–protein and protein–RNA complexes. Here, the crystal structure of the MIF4G domain of T. cruzi EIF4G5 is described at 2.4 Å resolution, which is the first three-dimensional structure of a trypanosomatid MIF4G domain to be reported. Structural comparison with IF4G homologs from other eukaryotes and other MIF4G-containing proteins reveals differences that may account for the specific interaction mechanisms of MIF4G despite its highly conserved overall fold.

Crystal Structure of the α Subunit of Human Translation Initiation Factor 2B

2009 ◽  
Vol 392 (4) ◽  
pp. 937-951 ◽  
Author(s):  
Takuya B. Hiyama ◽  
Takuhiro Ito ◽  
Hiroaki Imataka ◽  
Shigeyuki Yokoyama
Keyword(s):  
Crystal Structure ◽  
Translation Initiation ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Α Subunit
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