PDBsum entry 2g2k

Translation

PDB id: 2g2k

Contents

Protein chain

156 a.a. *

* Residue conservation analysis

PDB id:

2g2k

Name:

Translation

Title:

Nmr structure of an n-terminal fragment of the eukaryotic initiation factor 5 (eif5)

Structure:

Eukaryotic translation initiation factor 5. Chain: a. Fragment: n-terminal fragment, residues 1-170. Synonym: eif-5. Engineered: yes. Mutation: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 562

NMR struc:

18 models

Authors:

M.R.Conte,G.Kelly,J.Babon,D.Sanfelice,S.J.Smerdon,C.G.Proud

Key ref:

M.R.Conte et al. (2006). Structure of the eukaryotic initiation factor (eIF) 5 reveals a fold common to several translation factors. Biochemistry, 45, 4550-4558. PubMed id: 16584190 DOI: 10.1021/bi052387u

Date:

16-Feb-06 Release date: 13-Jun-06

Protein chain

P55010  (IF5_HUMAN) -  Eukaryotic translation initiation factor 5 from Homo sapiens

Seq: 431 a.a.

Struc: 156 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1021/bi052387u

Biochemistry 45:4550-4558 (2006)

PubMed id: 16584190

Structure of the eukaryotic initiation factor (eIF) 5 reveals a fold common to several translation factors.

M.R.Conte, G.Kelly, J.Babon, D.Sanfelice, J.Youell, S.J.Smerdon, C.G.Proud.

ABSTRACT

Eukaryotic initiation factor 5 (eIF5) plays multiple roles in translation initiation. Its N-terminal domain functions as a GTPase-activator protein (GAP) for GTP bound to eIF2, while its C-terminal region nucleates the interactions between multiple translation factors, including eIF1, which acts to inhibit GTP hydrolysis or P(i) release, and the beta subunit of eIF2. These proteins and the events in which they participate are critical for the accurate recognition of the correct start codon during translation initiation. Here, we report the three-dimensional solution structure of the N-terminal domain of human eIF5, comprising two subdomains, both reminiscent of nucleic-acid-binding modules. The N-terminal subdomain contains the "arginine finger" motif that is essential for GAP function but which, unusually, resides in a partially disordered region of the molecule. This implies that a conformational reordering of this portion of eIF5 is likely to occur upon formation of a competent complex for GTP hydrolysis, following the appropriate activation signal. Interestingly, the N-terminal subdomain of eIF5 reveals an alpha/beta fold structurally similar to both the archaeal orthologue of the beta subunit of eIF2 and, unexpectedly, to eIF1. These results reveal a novel protein fold common to several factors involved in related steps of translation initiation. The implications of these observations are discussed in terms of the mechanism of translation initiation.