Maize mitochondrial seryl-tRNA synthetase recognizes Escherichia coli tRNA(Ser) in vivo and in vitro.
In our studies to analyze the structure/function relationships among cytoplasmic and organellar seryl-tRNA synthetases (SerRS), we have characterized a Zea mays cDNA (SerZMm) encoding a protein with significant similarity to prokaryotic SerRS enzymes. To demonstrate the functional identity of SerZMm, the gene sequence encoding the putative mature protein was cloned. This construct complemented in vivo a temperature-sensitive Escherichia coli serS mutant strain. The mature SerZMm protein overexpressed in Escherichia coli efficiently aminoacylated bacterial tRNA(Ser) in vitro, while yeast tRNA was a poor substrate. These data identify SerZMm as an organellar maize seryl-tRNA synthetase, the first plant organellar SerRS to be cloned. The analysis of its N-terminal targeting signal suggests a mitochondrial function for the SerZMm protein in maize.
Rokov
J
J
Department of Chemistry, Faculty of Science, University of Zagreb, Rudjer Bosković Institute, Croatia.
Söll
D
D
Weygand-Durasević
I
I
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D008928:Mitochondria / Q000201:enzymology; D008969:Molecular Sequence Data; D009154:Mutation; D012329:RNA, Bacterial / Q000378:metabolism; D012362:RNA, Transfer, Ser / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012714:Serine-tRNA Ligase / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D013379:Substrate Specificity; D003313:Zea mays / Q000201:enzymology* / Q000235:genetics
D018076:DNA, Complementary; D012329:RNA, Bacterial; D012362:RNA, Transfer, Ser; D012714:Serine-tRNA Ligase