Translation initiation factor eIF-5A from Plasmodium falciparum.
Eukaryotic translation initiation factor (eIF-5A) is a highly conserved and essential protein that contains the unique amino acid hypusine. The first step in the post-translational biosynthesis of hypusine, the transfer of an aminobutyl moiety from the polyamine substrate spermidine to the -amino group of a specific lysine residue in the eIF-5A precursor, is catalyzed by the enzyme deoxyhypusine synthase. A cDNA encoding a protein homologous to eIF-5A was isolated by plaque hybridization from a cDNA library of Plasmodium falciparum. The cloned cDNA contains an open reading frame encoding a protein of 161 amino acids, which shares a high sequence identity with other eukaryotic eIF-5A sequences. A phylogenetic tree constructed with eIF-5A from P. falciparum and 16 other eIF-5A sequences of eukaryotic and archaeal origin reveals that plasmodial eIF-5A together with other apicomplexan eIF-5A show a higher degree of homology to plant proteins than to animal and fungal sequences. The plasmodial eIF-5A gene was expressed as a six-histidine tagged fusion protein in Escherichia coli. Radioactive incorporation studies with [1,8-3H] spermidine indicated that this protein can serve as a substrate for human deoxyhypusine synthase. Results of quantitative real-time PCR studies with synchronized erythrocytic stages of P. falciparum revealed no significant induction or downregulation but only some variation in the expression level of plasmodial eIF-5A in ring, trophozoite and schizont stage.
Department of Pharmaceutical Biology, University of Bonn, Nussallee 6, D-53115, Germany. i.molitor@uni-bonn.de
Ilka M
IM
Molitor
Sebastian
S
Knöbel
Chantip
C
Dang
Tobias
T
Spielmann
Axel
A
Alléra
Gabriele M
GM
König
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D017124:Conserved Sequence; D016054:DNA, Protozoan / Q000032:analysis / Q000737:chemistry; D004912:Erythrocytes / Q000469:parasitology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D010963:Plasmodium falciparum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D016053:RNA, Protozoan / Q000032:analysis; D016601:RNA-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013095:Spermidine / Q000378:metabolism; D000097574:Eukaryotic Translation Initiation Factor 5A
D016054:DNA, Protozoan; D000587:Oxidoreductases Acting on CH-NH Group Donors; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D016053:RNA, Protozoan; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D013095:Spermidine; D000097574:Eukaryotic Translation Initiation Factor 5A; C063507:deoxyhypusine synthase