2aho
From Proteopedia
Structure of the archaeal initiation factor eIF2 alpha-gamma heterodimer from Sulfolobus solfataricus complexed with GDPNP
Overview
Eukaryotic and archaeal initiation factors 2 (e/aIF2) are heterotrimeric proteins (alphabetagamma) supplying the small subunit of the ribosome with methionylated initiator tRNA. This study reports the crystallographic structure of an aIF2alphagamma heterodimer from Sulfolobus solfataricus bound to Gpp(NH)p-Mg(2+). aIF2gamma is in a closed conformation with the G domain packed on domains II and III. The C-terminal domain of aIF2alpha interacts with domain II of aIF2gamma. Conformations of the two switch regions involved in GTP binding are similar to those encountered in an EF1A:GTP:Phe-tRNA(Phe) complex. Comparison with the EF1A structure suggests that only the gamma subunit of the aIF2alphagamma heterodimer contacts tRNA. Because the alpha subunit markedly reinforces the affinity of tRNA for the gamma subunit, a contribution of the alpha subunit to the switch movements observed in the gamma structure is considered.
About this Structure
2AHO is a Protein complex structure of sequences from Sulfolobus solfataricus. Full crystallographic information is available from OCA.
Reference
Structural switch of the gamma subunit in an archaeal aIF2 alpha gamma heterodimer., Yatime L, Mechulam Y, Blanquet S, Schmitt E, Structure. 2006 Jan;14(1):119-28. PMID:16407071 Page seeded by OCA on Sat May 3 19:03:39 2008
