An archaeal protein homologous to mammalian SRP54 and bacterial Ffh recognizes a highly conserved region of SRP RNA.
The gene encoding the 54 kDa protein of signal recognition particle (SRP54) in the hyperthermophilic archaeon Pyrococcus furiosus has been cloned and sequenced. Recombinant P. furiosus SRP54 (pf-SRP54) and the N-terminal G-domain and C-terminal M-domain (pf-SRP54M) of pf-SRP54 with an amino-terminal addition of six histidine residues were expressed in Escherichia coli and subjected to binding experiments for SRP RNA, non-conserved 213-nucleotide RNA (helices 1, 2, 3, 4 and 5) and conserved 107-nucleotide RNA (helices 6 and 8) from SRP RNA. The RNA binding properties of the purified protein were determined by filter binding assays. The histidine-tagged pf-SRP54M bound specifically to the conserved 107-nucleotide RNA in the absence of pf-SRP19, unlike the eukaryotic homologue, with an apparent binding constant (K) of 18 nM.
Maeshima
H
H
School of Bioresources, Hiroshima Prefectural University, Shobara City, 727-0023, Hiroshima, Japan.
Okuno
E
E
Aimi
T
T
Morinaga
T
T
Itoh
T
T
D000595:Amino Acid Sequence; D000818:Animals; D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D017124:Conserved Sequence; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008322:Mammals; D008715:Methionine; D008969:Molecular Sequence Data; D020027:Pyrococcus furiosus / Q000235:genetics*; D012313:RNA / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D018271:Signal Recognition Particle / Q000235:genetics* / Q000378:metabolism
D019843:Archaeal Proteins; D029968:Escherichia coli Proteins; C082931:Ffh protein, E coli; C117074:SRP19 protein, human; C069268:SRP54 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D018271:Signal Recognition Particle; D012313:RNA; D008715:Methionine