Download MendeleyStructure of translation initiation factor 5A from Pyrobaculum aerophilum at 1.75 A resolution.
Peat, T.S., Newman, J., Waldo, G.S., Berendzen, J., Terwilliger, T.C.(1998) Structure 6: 1207-1214
- PubMed: 9753699
- DOI: https://doi.org/10.1016/s0969-2126(98)00120-8
- Primary Citation of Related Structures:
1BKB - PubMed Abstract:
Translation initiation factor 5A (IF-5A) is reported to be involved in the first step of peptide bond formation in translation, to be involved in cell-cycle regulation and to be a cofactor for the Rev and Rex transactivator proteins of human immunodeficiency virus-1 and T-cell leukemia virus I, respectively. IF-5A contains an unusual amino acid, hypusine (N-epsilon-(4-aminobutyl-2-hydroxy)lysine), that is required for its function. The first step in the post-translational modification of lysine to hypusine is catalyzed by the enzyme deoxyhypusine synthase, the structure of which has been published recently. IF-5A from the archebacterium Pyrobaculum aerophilum has been heterologously expressed in Escherichia coli with selenomethionine substitution. The crystal structure of IF-5A has been determined by multiwavelength anomalous diffraction and refined to 1.75 A. Unmodified P. aerophilum IF-5A is found to be a beta structure with two domains and three separate hydrophobic cores. The lysine (Lys42) that is post-translationally modified by deoxyhypusine synthase is found at one end of the IF-5A molecule in an turn between beta strands beta4 and beta5; this lysine residue is freely solvent accessible. The C-terminal domain is found to be homologous to the cold-shock protein CspA of E. coli, which has a well characterized RNA-binding fold, suggesting that IF-5A is involved in RNA binding.
Organizational Affiliation:
Life Sciences Division Los Alamos National Laboratory Mail Stop M888, Los Alamos, New Mexico, 87545, USA peat@proi1.lanl.gov
