2g2k
NMR structure of an N-terminal fragment of the eukaryotic initiation factor 5 (eIF5)
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OverviewOverview
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.
About this StructureAbout this Structure
2G2K is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Structure of the eukaryotic initiation factor (eIF) 5 reveals a fold common to several translation factors., Conte MR, Kelly G, Babon J, Sanfelice D, Youell J, Smerdon SJ, Proud CG, Biochemistry. 2006 Apr 11;45(14):4550-8. PMID:16584190
Page seeded by OCA on Mon Nov 12 22:13:52 2007