PDBsum entry 1b64

Guanine nucleotide exchange factor

PDB id: 1b64

Contents

Protein chain

91 a.a. *

* Residue conservation analysis

PDB id:

1b64

Name:

Guanine nucleotide exchange factor

Title:

Solution structure of the guanine nucleotide exchange factor domain from human elongation factor-one beta, nmr, 20 structures

Structure:

Elongation factor 1-beta. Chain: a. Fragment: guanine exchange factor domain. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Cell_line: bl21. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

NMR struc:

20 models

Authors:

J.M.J.Perez,G.Siegal,J.Kriek,K.Hard,J.Dijk,G.W.Canters,W.Moller

Key ref:

J.M.Pérez et al. (1999). The solution structure of the guanine nucleotide exchange domain of human elongation factor 1beta reveals a striking resemblance to that of EF-Ts from Escherichia coli. Structure, 7, 217-226. PubMed id: 10368288 DOI: 10.1016/S0969-2126(99)80027-6

Date:

20-Jan-99 Release date: 18-May-99

Protein chain

P24534  (EF1B_HUMAN) -  Elongation factor 1-beta from Homo sapiens

Seq: 225 a.a.

Struc: 91 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/S0969-2126(99)80027-6

Structure 7:217-226 (1999)

PubMed id: 10368288

The solution structure of the guanine nucleotide exchange domain of human elongation factor 1beta reveals a striking resemblance to that of EF-Ts from Escherichia coli.

J.M.Pérez, G.Siegal, J.Kriek, K.Hård, J.Dijk, G.W.Canters, W.Möller.

ABSTRACT

BACKGROUND: In eukaryotic protein synthesis, the multi-subunit elongation factor 1 (EF-1) plays an important role in ensuring the fidelity and regulating the rate of translation. EF-1alpha, which transports the aminoacyl tRNA to the ribosome, is a member of the G-protein superfamily. EF-1beta regulates the activity of EF-1alpha by catalyzing the exchange of GDP for GTP and thereby regenerating the active form of EF-1alpha. The structure of the bacterial analog of EF-1alpha, EF-Tu has been solved in complex with its GDP exchange factor, EF-Ts. These structures indicate a mechanism for GDP-GTP exchange in prokaryotes. Although there is good sequence conservation between EF-1alpha and EF-Tu, there is essentially no sequence similarity between EF-1beta and EF-Ts. We wished to explore whether the prokaryotic exchange mechanism could shed any light on the mechanism of eukaryotic translation elongation. RESULTS: Here, we report the structure of the guanine-nucleotide exchange factor (GEF) domain of human EF-1beta (hEF-1beta, residues 135-224); hEF-1beta[135-224], determined by nuclear magnetic resonance spectroscopy. Sequence conservation analysis of the GEF domains of EF-1 subunits beta and delta from widely divergent organisms indicates that the most highly conserved residues are in two loop regions. Intriguingly, hEF-1beta[135-224] shares structural homology with the GEF domain of EF-Ts despite their different primary sequences. CONCLUSIONS: On the basis of both the structural homology between EF-Ts and hEF-1beta[135-224] and the sequence conservation analysis, we propose that the mechanism of guanine-nucleotide exchange in protein synthesis has been conserved in prokaryotes and eukaryotes. In particular, Tyr181 of hEF-1beta[135-224] appears to be analogous to Phe81 of Escherichia coli EF-Ts.

Selected figure(s)

Figure 6.
Figure 6. Comparison of the tertiary structure of EF-1β and the GEF domain of EF-Ts. (a) Side-by-side ribbon diagrams of the GEF domain of E. coli EF-Ts (residues 57–139) and hEF-1β[135–224]. The structure on the left is the GEF-domain of EF-Ts (α helices in red and yellow, β sheet in cyan) from the complex with EF-Tu [20] . The sPhe81 sidechain is shown in dark blue. The mean structure of hEF-1β[135–224] (α helices in green and yellow, β sheet in dark blue) is shown on the right, with the loop between β2 and β3 in magenta and the sidechain of Tyr181 in yellow. (b) Superposition of the GEF domain of EF-Ts and hEF-1β[135–224]. The color scheme is identical to that in (a). Nineteen Cα atoms from each structure were chosen for a least-squares superposition. This figure was prepared using the program MOLMOL [54] .

The above figure is reprinted by permission from Cell Press: Structure (1999, 7, 217-226) copyright 1999.

Figure was selected by an automated process.