C-terminal portion of human eIF4GI

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
(New page: 200px <!-- The line below this paragraph, containing "STRUCTURE_1ug3", creates the "Structure Box" on the page. You may change the PDB parameter (which sets the PD...)
Line 1: Line 1:
-
[[Image:1ug3.png|left|200px]]
+
<StructureSection load='1ug3' size='400' side='right' scene= caption=''>
-
<!--
+
[[Image:1ug3.png|left|200px]]
-
The line below this paragraph, containing "STRUCTURE_1ug3", creates the "Structure Box" on the page.
+
-
You may change the PDB parameter (which sets the PDB file loaded into the applet)
+
-
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
+
-
or leave the SCENE parameter empty for the default display.
+
-
-->
+
-
{{STRUCTURE_1ug3| PDB=1ug3 | SCENE=1ug3/Cv/1 }}
+
-
===C-terminal portion of human eIF4GI===
+
===C-terminal portion of human eIF4GI ([[1ug3]])===
The X-ray structure of the C-terminal region of human eukaryotic translation initiation factor 4G (eIF4G) has been determined at 2.2 A resolution, revealing two atypical HEAT-repeat domains. eIF4G recruits various translation factors and the 40S ribosomal subunit to the mRNA 5' end. In higher eukaryotes, the C terminus of eIF4G (4G/C) supports translational regulation by recruiting eIF4A, an RNA helicase, and Mnk1, the kinase responsible for phosphorylating eIF4E. Structure-guided surface mutagenesis and protein-protein interaction assays were used to identify binding sites for eIF4A and Mnk1 within the HEAT-repeats of 4G/C. p97/DAP5, a translational modulator homologous to eIF4G, lacks an eIF4A binding site in the corresponding region. The second atypical HEAT domain of the 4G/C binds Mnk1 using two conserved aromatic/acidic-box (AA-box) motifs. Within the first AA-box, the aromatic residues contribute to the hydrophobic core of the domain, while the acidic residues form a negatively charged surface feature suitable for electrostatic interactions with basic residues in Mnk1.
The X-ray structure of the C-terminal region of human eukaryotic translation initiation factor 4G (eIF4G) has been determined at 2.2 A resolution, revealing two atypical HEAT-repeat domains. eIF4G recruits various translation factors and the 40S ribosomal subunit to the mRNA 5' end. In higher eukaryotes, the C terminus of eIF4G (4G/C) supports translational regulation by recruiting eIF4A, an RNA helicase, and Mnk1, the kinase responsible for phosphorylating eIF4E. Structure-guided surface mutagenesis and protein-protein interaction assays were used to identify binding sites for eIF4A and Mnk1 within the HEAT-repeats of 4G/C. p97/DAP5, a translational modulator homologous to eIF4G, lacks an eIF4A binding site in the corresponding region. The second atypical HEAT domain of the 4G/C binds Mnk1 using two conserved aromatic/acidic-box (AA-box) motifs. Within the first AA-box, the aromatic residues contribute to the hydrophobic core of the domain, while the acidic residues form a negatively charged surface feature suitable for electrostatic interactions with basic residues in Mnk1.
Line 21: Line 15:
'''Protease cleavage sites''' (especially caspase cleavage sites) are frequently situated in '''flexible, unstructured regions''' of proteins. In eIF4GI, eIF2Bε, and eIF5, where the caspase cleavage site is absent, <scene name='3d3m/Al1/2'>this region</scene> is structured and characterized by an α3-α4 interunit loop. The superposition of <font color='blue'><b>α3 and α4 of eIF4GI</b></font> ([[1ug3]], <font color='blue'><b>blue</b></font>) to <font color='orange'><b>α3 (orange)</b></font> and <font color='lime'><b>α4 (lime)</b></font> of C-terminal domain of human DAP5/p97 (DAP5-CTD, [[3d3m]]) is shown.
'''Protease cleavage sites''' (especially caspase cleavage sites) are frequently situated in '''flexible, unstructured regions''' of proteins. In eIF4GI, eIF2Bε, and eIF5, where the caspase cleavage site is absent, <scene name='3d3m/Al1/2'>this region</scene> is structured and characterized by an α3-α4 interunit loop. The superposition of <font color='blue'><b>α3 and α4 of eIF4GI</b></font> ([[1ug3]], <font color='blue'><b>blue</b></font>) to <font color='orange'><b>α3 (orange)</b></font> and <font color='lime'><b>α4 (lime)</b></font> of C-terminal domain of human DAP5/p97 (DAP5-CTD, [[3d3m]]) is shown.
There are only 3 pairs of <scene name='3d3m/Al1/3'>interacting residues</scene> between α3 and α4 of DAP5-CTD. In contrast, there are more interactions at the <scene name='3d3m/Al1/4'>loop</scene> stabilizing the interaction between α3 and α4 in eIF4GI.
There are only 3 pairs of <scene name='3d3m/Al1/3'>interacting residues</scene> between α3 and α4 of DAP5-CTD. In contrast, there are more interactions at the <scene name='3d3m/Al1/4'>loop</scene> stabilizing the interaction between α3 and α4 in eIF4GI.
 +
</StructureSection>
==Reference==
==Reference==

Revision as of 15:39, 7 June 2012

PDB ID 1ug3

Drag the structure with the mouse to rotate

Reference

  • Bellsolell L, Cho-Park PF, Poulin F, Sonenberg N, Burley SK. Two structurally atypical HEAT domains in the C-terminal portion of human eIF4G support binding to eIF4A and Mnk1. Structure. 2006 May;14(5):913-23. PMID:16698552 doi:10.1016/j.str.2006.03.012

Proteopedia Page Contributors and Editors (what is this?)

Alexander Berchansky, Michal Harel

Retrieved from "http://52.214.119.220/wiki/index.php/C-terminal_portion_of_human_eIF4GI"
Personal tools