KEGG ENZYME: 3.6.5.3

ENZYME: 3.6.5.3

Entry

EC 3.6.5.3                  Enzyme

Name

protein-synthesizing GTPase;
elongation factor (EF);
initiation factor (IF);
peptide-release or termination factor

Class

Hydrolases;
Acting on acid anhydrides;
Acting on GTP to facilitate cellular and subcellular movement

Sysname

GTP phosphohydrolase (mRNA-translation-assisting)

Reaction(IUBMB)

GTP + H2O = GDP + phosphate [RN:R00335]

Reaction(KEGG)

R00335

Substrate

GTP [CPD:C00044];
H2O [CPD:C00001]

Product

GDP [CPD:C00035];
phosphate [CPD:C00009]

Comment

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 hydrolyses it in prokaryotes. In eukaryotes, it is eIF-2 (150 kDa) that binds GTP. In the elongation phase, the GTP-hydrolysing 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 catalyse binding of aminoacyl-tRNA to the ribosomal A-site, while EF-G and EF-2 catalyse 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.

History

EC 3.6.5.3 created 2000 as EC 3.6.1.48, transferred 2003 to EC 3.6.5.3

Reference

1 [PMID:6566615]

Authors

Kurzchalia TV, Bommer UA, Babkina GT, Karpova GG.

Title

GTP interacts with the gamma-subunit of eukaryotic initiation factor eIF-2.

Journal

FEBS Lett 175:313-6 (1984)
DOI:10.1016/0014-5793(84)80758-9

Reference

2 [PMID:8722024]

Authors

Kisselev LL, Frolova LYu.

Title

Termination of translation in eukaryotes.

Journal

Biochem Cell Biol 73:1079-86 (1995)
DOI:10.1139/o95-116

Reference

3 [PMID:8985244]

Authors

Rodnina MV, Savelsbergh A, Katunin VI, Wintermeyer W.

Title

Hydrolysis of GTP by elongation factor G drives tRNA movement on the ribosome.

Journal

Nature 385:37-41 (1997)
DOI:10.1038/385037a0

Reference

4 [PMID:9233821]

Authors

Freistroffer DV, Pavlov MY, MacDougall J, Buckingham RH, Ehrenberg M.

Title

Release factor RF3 in E.coli accelerates the dissociation of release factors RF1 and RF2 from the ribosome in a GTP-dependent manner.

Journal

EMBO J 16:4126-33 (1997)
DOI:10.1093/emboj/16.13.4126

Reference

5 [PMID:9838020]

Authors

Krab IM, Parmeggiani A.

Title

EF-Tu, a GTPase odyssey.

Journal

Biochim Biophys Acta 1443:1-22 (1998)
DOI:10.1016/S0167-4781(98)00169-9

Other DBs

ExplorEnz - The Enzyme Database:

3.6.5.3

IUBMB Enzyme Nomenclature:

3.6.5.3

ExPASy - ENZYME nomenclature database:

3.6.5.3

BRENDA, the Enzyme Database:

3.6.5.3

DBGET integrated database retrieval system