Structure of translation initiation factor 5A from Pyrobaculum aerophilum at 1.75 A resolution.
Structure
; 6(9): 1207-14, 1998 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-9753699
ABSTRACT
BACKGROUND:
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.
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Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Fatores de Iniciação de Peptídeos
/
Proteínas de Ligação a RNA
/
Thermoproteaceae
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Structure
Ano de publicação:
1998
Tipo de documento:
Article