1bkb
INITIATION FACTOR 5A FROM ARCHEBACTERIUM PYROBACULUM AEROPHILUMINITIATION FACTOR 5A FROM ARCHEBACTERIUM PYROBACULUM AEROPHILUM
Structural highlights
FunctionIF5A_PYRAE Functions by promoting the formation of the first peptide bond. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: 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. RESULTS: 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. CONCLUSIONS: 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. Structure of translation initiation factor 5A from Pyrobaculum aerophilum at 1.75 A resolution.,Peat TS, Newman J, Waldo GS, Berendzen J, Terwilliger TC Structure. 1998 Sep 15;6(9):1207-14. PMID:9753699[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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