P32481 · IF2G_YEAST

Function

function

As a subunit of eukaryotic initiation factor 2 eIF2, involved in the early steps of protein synthesis. In the presence of GTP, eIF-2 forms a ternary complex with initiator tRNA Met-tRNAi and then recruits the 40S ribosomal complex and initiation factors eIF-1, eIF-1A and eIF-3 to form the 43S pre-initiation complex (43S PIC), a step that determines the rate of protein translation. The 43S PIC binds to mRNA and scans downstream to the initiation codon, where it forms a 48S initiation complex by codon-anticodon base pairing. This leads to the displacement of eIF-1 to allow GTPase-activating protein (GAP) eIF-5-mediated hydrolysis of eIF2-bound GTP. Hydrolysis of GTP and release of Pi, which makes GTP hydrolysis irreversible, causes the release of the eIF-2-GDP binary complex from the 40S subunit, an event that is essential for the subsequent joining of the 60S ribosomal subunit to form an elongation-competent 80S ribosome. In order for eIF-2 to recycle and catalyze another round of initiation, the GDP bound to eIF-2 must be exchanged with GTP by way of a reaction catalyzed by GDP-GTP exchange factor (GEF) eIF-2B.

Miscellaneous

Present with 20800 molecules/cell in log phase SD medium.

Catalytic activity

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site110-115GTP (UniProtKB | ChEBI)
Binding site249-252GTP (UniProtKB | ChEBI)
Binding site284-286GTP (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentcytosol
Cellular Componenteukaryotic 43S preinitiation complex
Cellular Componenteukaryotic 48S preinitiation complex
Cellular Componenteukaryotic translation initiation factor 2 complex
Cellular Componentmulti-eIF complex
Cellular Componentribosome
Molecular FunctionGTP binding
Molecular FunctionGTPase activity
Molecular Functionmethionyl-initiator methionine tRNA binding
Molecular Functiontranslation initiation factor activity
Molecular Functiontranslation initiation factor binding
Biological Processformation of translation preinitiation complex
Biological Processpositive regulation of translational fidelity
Biological Processtranslational initiation

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Eukaryotic translation initiation factor 2 subunit gamma
  • EC number
  • Short names
    eIF2-gamma

Gene names

    • Name
      GCD11
    • Synonyms
      SUI4, TIF213
    • Ordered locus names
      YER025W

Organism names

Accessions

  • Primary accession
    P32481
  • Secondary accessions
    • D3DLS4

Proteomes

Organism-specific databases

Phenotypes & Variants

Disruption phenotype

Inviable.

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis135In SUI4; defective in ternary complex formation, correlating with a higher rate of dissociation from charged initiator-tRNA in the absence of GTP hydrolysis.
Mutagenesis142Reduces the affinity of eIF-2 for Met-tRNAi(Met) without affecting the k(off) value for guanine nucleotides.
Mutagenesis203Impairs eIF2 complex function. Reduces cell population growth.
Mutagenesis203No effect on cell population growth.
Mutagenesis218No effect on cell population growth.
Mutagenesis218Impairs eIF2 complex function. Strongly reduces cell population growth.
Mutagenesis250Increases the off-rate for GDP, without altering the apparent dissociation constant for Met-tRNAi(Met). Mimicks the function of the guanine nucleotide exchange factor eIF-2B.
Mutagenesis281Impairs eIF2 complex formation by impairing binding to SUI3 but not SUI2. Reduces cell population growth.
Mutagenesis281Abolishes binding to SUI3 but not to SUI2 or CDC123. Abolishes interactions with the eIF2B complex subunits GCD6 and GCD7.
Mutagenesis281No effect on cell population growth.
Mutagenesis318Mildly impairs eIF2 complex function. No effect on cell population growth.
Mutagenesis318Impairs binding to methionyl-initiator methionine tRNA and impairs eIF2 complex function. Mildly reduces cell population growth.
Mutagenesis325-331Disrupts binding to CDC123 and SUI2. Does not affect interaction with SUI3.
Mutagenesis403Abolishes binding to SUI2 but not to SUI3 or CDC123. Abolishes interactions with the eIF2B complex subunits GCD6 and GCD7. Decreases cell population growth.
Mutagenesis490Mildly impairs eIF2 complex function.
Mutagenesis504Disrupts binding to CDC123.
Mutagenesis509Disrupts binding to CDC123.
Mutagenesis515-527Disrupts eIF2 complex formation and binding to CDC123.

PTM/Processing

Features

Showing features for chain, modified residue.

TypeIDPosition(s)Description
ChainPRO_00001374481-527Eukaryotic translation initiation factor 2 subunit gamma
Modified residue60Phosphothreonine
Modified residue258Phosphoserine

Keywords

Proteomic databases

PTM databases

Interaction

Subunit

Eukaryotic translation initiation factor 2 eIF2 is a heterotrimeric complex composed of an alpha, a beta and a gamma subunit (PubMed:11018020, PubMed:16522633, PubMed:23775072, PubMed:30517694, PubMed:35031321).
The factors eIF-1, eIF-1A, eIF-2, eIF-3, TIF5/eIF-5 and methionyl-tRNAi form a multifactor complex (MFC) that may bind to the 40S ribosome (PubMed:11018020, PubMed:16522633).
Interacts (via C-terminus) with CDC123; the interaction is direct (PubMed:23775072, PubMed:26211610, PubMed:35031321, PubMed:37507029).
Interacts with GCD1 (PubMed:23775072).
Interacts with the eIF2B complex subunits GCD6 and GCD7 (PubMed:35031321).
Interacts with methionyl-initiator methionine tRNA (PubMed:30517694).

Binary interactions

View interactors in UniProtKB
View CPX-427 in Complex Portal

Protein-protein interaction databases

Miscellaneous

Family & Domains

Features

Showing features for region, compositional bias, domain.

TypeIDPosition(s)Description
Region1-83Disordered
Compositional bias37-73Basic and acidic residues
Domain98-307tr-type G
Region107-114G1
Region135-139G2
Region193-196G3
Region249-252G4
Region284-286G5
Region515-527Interacts with CDC123

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    527
  • Mass (Da)
    57,866
  • Last updated
    1993-10-01 v1
  • Checksum
    D498AE62BC3E81CD
MSDLQDQEPSIIINGNLEPVGEPDIVEETEVVAQETQETQDADKPKKKVAFTGLEEDGETEEEKRKREFEEGGGLPEQPLNPDFSKLNPLSAEIINRQATINIGTIGHVAHGKSTVVRAISGVQTVRFKDELERNITIKLGYANAKIYKCQEPTCPEPDCYRSFKSDKEISPKCQRPGCPGRYKLVRHVSFVDCPGHDILMSTMLSGAAVMDAALLLIAGNESCPQPQTSEHLAAIEIMKLKHVIILQNKVDLMREESALEHQKSILKFIRGTIADGAPIVPISAQLKYNIDAVNEFIVKTIPVPPRDFMISPRLIVIRSFDVNKPGAEIEDLKGGVAGGSILNGVFKLGDEIEIRPGIVTKDDKGKIQCKPIFSNIVSLFAEQNDLKFAVPGGLIGVGTKVDPTLCRADRLVGQVVGAKGHLPNIYTDIEINYFLLRRLLGVKTDGQKQAKVRKLEPNEVLMVNIGSTATGARVVAVKADMARLQLTSPACTEINEKIALSRRIEKHWRLIGWATIKKGTTLEPIA

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias37-73Basic and acidic residues

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
L04268
EMBL· GenBank· DDBJ
AAA34633.1
EMBL· GenBank· DDBJ
Genomic DNA
U18778
EMBL· GenBank· DDBJ
AAB64558.1
EMBL· GenBank· DDBJ
Genomic DNA
BK006939
EMBL· GenBank· DDBJ
DAA07678.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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