Association of an aminoacyl-tRNA synthetase with a putative metabolic protein in archaea.
Aminoacyl-tRNA synthetases are essential enzymes that catalyze attachment of amino acids to tRNAs for decoding of genetic information. In higher eukaryotes, several synthetases associate with non-synthetase proteins to form a high-molecular mass complex that may improve the efficiency of protein synthesis. This multi-synthetase complex is not found in bacteria. Here we describe the isolation of a non-synthetase protein from the archaeon Methanocaldococcus jannaschii that was copurified with prolyl-tRNA synthetase (ProRS). This protein, Mj1338, also interacts with several other tRNA synthetases and has an affinity for general tRNA, suggesting the possibility of forming a multi-synthetase complex. However, unlike the non-synthetase proteins in the eukaryotic complex, the protein Mj1338 is predicted to be a metabolic protein, related to members of the family of H(2)-forming N(5),N(10)-methylene tetrahydromethanopterin (5,10-CH(2)-H(4)MP) dehydrogenases that are involved in the one-carbon metabolism of the archaeon. The association of Mj1338 with ProRS, and with other components of the protein synthesis machinery, thus suggests the possibility of a closer link between metabolism and decoding in archaea than in eukarya or bacteria.
Lipman
Richard S A
RS
Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson University, 233 South 10th Street, BLSB 220, Philadelphia, Pennsylvania 19107, USA.
Chen
Jing
J
Evilia
Caryn
C
Vitseva
Olga
O
Hou
Ya-Ming
YM
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000604:Amino Acyl-tRNA Synthetases / Q000302:isolation & purification / Q000378:metabolism*; D019843:Archaeal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D006801:Humans; D007700:Kinetics; D017016:Methanococcaceae / Q000201:enzymology*; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012343:RNA, Transfer / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D019843:Archaeal Proteins; D011994:Recombinant Proteins; D012343:RNA, Transfer; D010088:Oxidoreductases; D000604:Amino Acyl-tRNA Synthetases