An "elongated" translation elongation factor Tu for truncated tRNAs in nematode mitochondria.
We have found the gene for a translation elongation factor Tu (EF-Tu) homologue in the genome of the nematode Caenorhabditis elegans. Because the corresponding protein was detected immunologically in a nematode mitochondrial (mt) extract, it could be regarded as a nematode mt EF-Tu. The protein possesses an extension of about 57 amino acids (we call this domain 3') at the C terminus, which is not found in any other known EF-Tu. Because most nematode mt tRNAs lack a T stem, domain 3' may be related to this feature. The nematode EF-Tu bound to nematode T stem-lacking tRNA, but bacterial EF-Tu was unable to do so. A series of domain exchange experiments strongly suggested that domains 3 and 3' are essential for binding to T stem-lacking tRNAs. This finding may constitute a novel example of the co-evolution of a structurally simplified RNA and the cognate RNA-binding protein, the latter having apparently acquired an additional domain to compensate for the lack of a binding site(s) on the RNA.
Ohtsuki
T
T
Department of Chemistry, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
Watanabe Yi
Takemoto
C
C
Kawai
G
G
Ueda
T
T
Kita
K
K
Kojima
S
S
Kaziro
Y
Y
Nyborg
J
J
Watanabe
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000235:genetics; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism; D002417:Cattle; D003001:Cloning, Molecular; D017931:DNA Primers; D018509:DNA, Helminth / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010444:Peptide Elongation Factor Tu / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry / Q000235:genetics*; D000077278:RNA, Mitochondrial; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D018509:DNA, Helminth; D004272:DNA, Mitochondrial; D015801:Helminth Proteins; D000077278:RNA, Mitochondrial; D011994:Recombinant Proteins; D012313:RNA; D012343:RNA, Transfer; D010444:Peptide Elongation Factor Tu