Domain structure in yeast tRNA ligase.
Yeast tRNA ligase is one of two proteins required for the splicing of precursor tRNA molecules containing introns. The 95-kDa tRNA ligase has been purified to homogeneity from a strain of Escherichia coli which overexpresses the protein. The ligation reaction requires three enzymatic activities: phosphodiesterase, polynucleotide kinase, and ligase. By partial proteolytic digestion, we have produced fragments of tRNA ligase which contain the constituent activities. These results provide evidence for a model in which the three constituent activities of ligase are located in three distinct domains separated by protease-sensitive regions. We have also located the active adenylylated site in the ligase domains. It is lysine-114. The tRNA ligase sequence in this region has limited homology to the active-site region of T4 RNA ligase.
Division of Biology, California Institute of Technology, Pasadena 91125.
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D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011130:RNA Ligase (ATP) / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D013604:T-Phages / Q000201:enzymology / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
D005656:Fungal Proteins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D000255:Adenosine Triphosphate; D011130:RNA Ligase (ATP)