Expasy logo

ENZYME

ENZYME entry: EC 3.6.5.3

Accepted Name
protein-synthesizing GTPase
Alternative Name(s)
elongation factor (EF)
initiation factor (IF)
peptide-release factor (RF)
peptide-release or termination factor
Reaction catalysed
GTP + H2O <=> GDP + H(+) + phosphate
Comment(s)
  • This enzyme comprises a family of proteins involved in prokaryotic as well as eukaryotic protein synthesis.
  • In the initiation factor complex, it is IF-2b (98 kDa) that binds GTP and subsequently hydrolyzes it in prokaryotes.
  • In eukaryotes, it is eIF-2 (150 kDa) that binds GTP.
  • In the elongation phase, the GTP-hydrolyzing proteins are the EF-Tu polypeptide of the prokaryotic transfer factor (43 kDa), the eukaryotic elongation factor EF-1alpha (53 kDa), the prokaryotic EF-G (77 kDa), the eukaryotic EF-2 (70-110 kDa) and the signal recognition particle that play a role in endoplasmic reticulum protein synthesis (325 kDa).
  • EF-Tu and EF-1alpha catalyze binding of aminoacyl-tRNA to the ribosomal A-site, while EF-G and EF-2 catalyze the translocation of peptidyl-tRNA from the A-site to the P-site.
  • GTPase activity is also involved in polypeptide release from the ribosome with the aid of the pRFs and eRFs.
  • Formerly EC 3.6.1.48.
Cross-references
BRENDA3.6.5.3
EC2PDB3.6.5.3
ExplorEnz3.6.5.3
PRIAM enzyme-specific profiles3.6.5.3
KEGG Ligand Database for Enzyme Nomenclature3.6.5.3
IUBMB Enzyme Nomenclature3.6.5.3
IntEnz3.6.5.3
MEDLINEFind literature relating to 3.6.5.3
MetaCyc3.6.5.3
Rhea expert-curated reactions3.6.5.3
UniProtKB/Swiss-Prot
Q2VIR3, IF2GL_HUMANQ9Y9C1, IF2G_AERPEO29663, IF2G_ARCFU
Q2KHU8, IF2G_BOVINQ5ZMS3, IF2G_CHICKJ9VR81, IF2G_CRYNH
F1QGW6, IF2G_DANREQ54XD8, IF2G_DICDIQ24208, IF2G_DROME
O96719, IF2G_ENCCUB9LSM6, IF2G_HALLTQ5UYS2, IF2G_HALMA
B0R6Y7, IF2G_HALS3Q9HNK9, IF2G_HALSAQ18KI6, IF2G_HALWD
P41091, IF2G_HUMANA6UTL4, IF2G_META3Q8TJT7, IF2G_METAC
Q58657, IF2G_METJAQ8TVE5, IF2G_METKAA4FWW9, IF2G_METM5
A9AAA4, IF2G_METM6A6VGE8, IF2G_METM7Q8PZA0, IF2G_METMA
Q6LXY6, IF2G_METMPO26361, IF2G_METTHA6UPK8, IF2G_METVS
Q9Z0N1, IF2G_MOUSEQ3IMM5, IF2G_NATPDQ5R797, IF2G_PONAB
Q9V1G0, IF2G_PYRABQ8U082, IF2G_PYRFUO59410, IF2G_PYRHO
P81795, IF2G_RATQ980A5, IF2G_SACS2Q09130, IF2G_SCHPO
O36041, IF2G_SPIVOQ975N8, IF2G_SULTOQ9HLA7, IF2G_THEAC
Q5JDL3, IF2G_THEKOB6YW69, IF2G_THEONQ978W8, IF2G_THEVO
P32481, IF2G_YEASTQ9Z0N2, IF2H_MOUSEC9WPN6, IF2H_RAT
G0S8G9, IF2P_CHATDQ54XP6, IF2P_DICDIO60841, IF2P_HUMAN
Q05D44, IF2P_MOUSEQ5RDE1, IF2P_PONABB2GUV7, IF2P_RAT
Q10251, IF2P_SCHPOP39730, IF2P_YEAST

View entry in original ENZYME format
View entry in raw text format (no links)
All UniProtKB/Swiss-Prot entries referenced in this entry, with possibility to download in different formats, align etc.
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 3.6.5.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 3.6.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 3.-.-.-