AC   MF_03001;
DC   Protein; auto
TR   HAMAP; MF_03001; -; 1; level=0
XX
Names: eIF3b
XX
ID   EIF3B
case <OC:Vertebrata>
DE   RecName: Full=Eukaryotic translation initiation factor 3 subunit B;
DE            Short=eIF3b;
DE   AltName: Full=Eukaryotic translation initiation factor 3 subunit 9;
DE   AltName: Full=eIF-3-eta;
else case <OC:Fungi>
DE   RecName: Full=Eukaryotic translation initiation factor 3 subunit B;
DE            Short=eIF3b;
DE   AltName: Full=Eukaryotic translation initiation factor 3 90 kDa subunit homolog;
DE            Short=eIF3 p90;
DE   AltName: Full=Translation initiation factor eIF3, p90 subunit homolog;
else case <OC:Viridiplantae>
DE   RecName: Full=Eukaryotic translation initiation factor 3 subunit B;
DE            Short=eIF3b;
DE   AltName: Full=eIF-3-eta;
DE   AltName: Full=eIF3 p110;
else
DE   RecName: Full=Eukaryotic translation initiation factor 3 subunit B;
DE            Short=eIF3b;
DE   AltName: Full=Eukaryotic translation initiation factor 3 subunit 9;
end case
case <OC:Vertebrata>
GN   Name=EIF3B; Synonyms=EIF3S9;
else case <OC:Caenorhabditis>
GN   Name=eif-3.B;
else case <OC:Drosophilidae>
GN   Name=eIF3b; Synonyms=eIF3-S9;
else case <OC:Fungi>
GN   Name=PRT1;
end case
XX
case <OC:Mammalia>
CC   -!- FUNCTION: RNA-binding component of the eukaryotic translation
CC       initiation factor 3 (eIF-3) complex, which is required for several
CC       steps in the initiation of protein synthesis. The eIF-3 complex
CC       associates with the 40S ribosome and facilitates the recruitment of
CC       eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S pre-
CC       initiation complex (43S PIC). The eIF-3 complex stimulates mRNA
CC       recruitment to the 43S PIC and scanning of the mRNA for AUG
CC       recognition. The eIF-3 complex is also required for disassembly and
CC       recycling of post-termination ribosomal complexes and subsequently
CC       prevents premature joining of the 40S and 60S ribosomal subunits prior
CC       to initiation. The eIF-3 complex specifically targets and initiates
CC       translation of a subset of mRNAs involved in cell proliferation,
CC       including cell cycling, differentiation and apoptosis, and uses
CC       different modes of RNA stem-loop binding to exert either translational
CC       activation or repression.
else
CC   -!- FUNCTION: RNA-binding component of the eukaryotic translation
CC       initiation factor 3 (eIF-3) complex, which is involved in protein
CC       synthesis of a specialized repertoire of mRNAs and, together with other
CC       initiation factors, stimulates binding of mRNA and methionyl-tRNAi to
CC       the 40S ribosome. The eIF-3 complex specifically targets and initiates
CC       translation of a subset of mRNAs involved in cell proliferation.
end case
case <OC:Mammalia>
CC   -!- SUBUNIT: Component of the eukaryotic translation initiation factor 3
CC       (eIF-3) complex, which is composed of 13 subunits: EIF3A, EIF3B, EIF3C,
CC       EIF3D, EIF3E, EIF3F, EIF3G, EIF3H, EIF3I, EIF3J, EIF3K, EIF3L and
CC       EIF3M. The eIF-3 complex appears to include 3 stable modules: module A
CC       is composed of EIF3A, EIF3B, EIF3G and EIF3I; module B is composed of
CC       EIF3F, EIF3H, and EIF3M; and module C is composed of EIF3C, EIF3D,
CC       EIF3E, EIF3K and EIF3L. EIF3C of module C binds EIF3B of module A and
CC       EIF3H of module B, thereby linking the three modules. EIF3J is a labile
CC       subunit that binds to the eIF-3 complex via EIF3B. The eIF-3 complex
CC       interacts with RPS6KB1 under conditions of nutrient depletion.
CC       Mitogenic stimulation leads to binding and activation of a complex
CC       composed of MTOR and RPTOR, leading to phosphorylation and release of
CC       RPS6KB1 and binding of EIF4B to eIF-3. Also interacts with UPF2.
CC       Interacts with METTL3.
else case <OC:Vertebrata> and not <OC:Mammalia>
CC   -!- SUBUNIT: Component of the eukaryotic translation initiation factor 3
CC       (eIF-3) complex, which is composed of 13 subunits: @gn(EIF3A),
CC       @gn(EIF3B), @gn(EIF3C), @gn(EIF3D), @gn(EIF3E), @gn(EIF3F), @gn(EIF3G),
CC       @gn(EIF3H), @gn(EIF3I), @gn(EIF3J), @gn(EIF3K), @gn(EIF3L) and
CC       @gn(EIF3M).
else case <OC:Drosophilidae>
CC   -!- SUBUNIT: Component of the eukaryotic translation initiation factor 3
CC       (eIF-3) complex. The eIF-3 complex interacts with pix.
else
CC   -!- SUBUNIT: Component of the eukaryotic translation initiation factor 3
CC       (eIF-3) complex.
end case
CC   -!- SUBCELLULAR LOCATION: Cytoplasm.
case <OC:Mammalia>
CC   -!- DOMAIN: The RRM domain mediates interaction with EIF3J.
CC   -!- PTM: Phosphorylated. Phosphorylation is enhanced upon serum
CC       stimulation.
end case
CC   -!- SIMILARITY: Belongs to the eIF-3 subunit B family.
XX
DR   PROSITE; PS50102; RRM; 1; trigger=yes
DR   PROSITE; PS00678; WD_REPEATS_1; 1; trigger=no
DR   PROSITE; PS50082; WD_REPEATS_2; 1; trigger=no
DR   PROSITE; PS50294; WD_REPEATS_REGION; 1; trigger=no
DR   Pfam; PF08662; eIF2A; 1; trigger=no
DR   Pfam; PF00076; RRM_1; 1; trigger=no
DR   REP; Repeat_WD40; WD40; 5-7; trigger=strict
XX
case <FTTag:acetyl>
KW   Acetylation
end case
KW   Cytoplasm
KW   Initiation factor
case <OC:Mammalia>
KW   Phosphoprotein
end case
KW   Protein biosynthesis
KW   RNA-binding
XX
GO   GO:0003723; F:RNA binding
GO   GO:0003743; F:translation initiation factor activity
GO   GO:0001732; P:formation of cytoplasmic translation initiation complex
GO   GO:0002183; P:cytoplasmic translational initiation
GO   GO:0005737; C:cytoplasm
GO   GO:0005852; C:eukaryotic translation initiation factor 3 complex
GO   GO:0016282; C:eukaryotic 43S preinitiation complex
GO   GO:0033290; C:eukaryotic 48S preinitiation complex
XX
FT   From: EIF3B_HUMAN (P55884)
case <OC:Mammalia>
FT   REGION          124..413
FT                   /note="Sufficient for interaction with EIF3E"
FT   REGION          170..274
FT                   /note="Sufficient for interaction with EIF3J"
FT   MOD_RES         1
FT                   /note="N-acetylmethionine"
FT   Tag: acetyl; Condition: M
FT   MOD_RES         83
FT                   /note="Phosphoserine"
FT   Condition: S
FT   MOD_RES         85
FT                   /note="Phosphoserine"
FT   Condition: S
FT   MOD_RES         119
FT                   /note="Phosphoserine"
FT   Condition: S
FT   MOD_RES         125
FT                   /note="Phosphoserine"
FT   Condition: S
FT   MOD_RES         152
FT                   /note="Phosphoserine"
FT   Condition: S
FT   MOD_RES         154
FT                   /note="Phosphoserine"
FT   Condition: S
FT   MOD_RES         164
FT                   /note="Phosphoserine"
FT   Condition: S
end case
FT   From: EIF3B_YEAST (P06103)
case <OC:Saccharomycetes>
FT   REGION          1..136
FT                   /note="Sufficient for interaction with HCR1 and TIF32"
FT   REGION          28..261
FT                   /note="Sufficient for interaction with PIC8"
end case
XX
Size: 621-814;
Related: None;
Template: P55884; Q8JZQ9; Q4G061; Q9XWI6; Q0E940; Q10425; P06103;
Scope:
 Eukaryota
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: None
Comments: None
XX
# Revision 1.17 2021/03/19
//