An essential surface motif (WAQKW) of yeast RNA triphosphatase mediates formation of the mRNA capping enzyme complex with RNA guanylyltransferase Journal Article
| Authors: | Ho, C. K.; Lehman, K.; Shuman, S. |
| Article Title: | An essential surface motif (WAQKW) of yeast RNA triphosphatase mediates formation of the mRNA capping enzyme complex with RNA guanylyltransferase |
| Abstract: | Saccharomyces cerevisiae RNA triphosphatase (Cet1p) and RNA guanylyltransferase (Ceg1p) interact in vivo and in vitro to form a bifunctional mRNA capping enzyme complex. Cet1p binding to Ceg1p stimulates the guanylyltransferase activity of Ceg1p. Here we localize the guanylyltransferase-binding and guanylyltransferase-stimulation functions of Cet1p to a 21-amino acid segment from residues 239 to 259. The guanylyltransferase-binding domain is located on the protein surface, as gauged by protease sensitivity, and is conserved in the Candida albicans RNA triphosphatase CaCet1p. Alanine-cluster mutations of a WAQKW motif within this segment abolish guanylyltransferase-binding in vitro and Cet1p function in vivo, but do not affect the triphosphatase activity of Cet1p. Proteolytic footprinting experiments provide physical evidence that Cet1p interacts with the C-terminal domain of Ceg1p. Trypsin-sensitive sites of Ceg1p that are shielded from proteolysis when Ceg1p is bound to Cet1p are located between nucleotidyl transferase motifs V and VI. |
| Keywords: | controlled study; unclassified drug; nonhuman; complex formation; phosphatase; carboxy terminal sequence; protein degradation; protein protein interaction; enzyme activation; rna triphosphatase; enzyme activity; acid anhydride hydrolases; amino acid sequence; conserved sequence; molecular sequence data; sequence homology, amino acid; kinetics; messenger rna; saccharomyces cerevisiae; sequence alignment; peptide fragments; recombinant proteins; binding site; mutagenesis, site-directed; alanine; candida albicans; yeast cell; nucleotidyltransferase; nucleotidyltransferases; chromatography, affinity; transferase; fungal enzyme; promoter regions (genetics); protein sorting signals; priority journal; article; rna guanyltransferase |
| Journal Title: | Nucleic Acids Research |
| Volume: | 27 |
| Issue: | 24 |
| ISSN: | 0305-1048 |
| Publisher: | Oxford University Press |
| Date Published: | 1999-12-01 |
| Start Page: | 4671 |
| End Page: | 4678 |
| Language: | English |
| PUBMED: | 10572165 |
| PROVIDER: | scopus |
| PMCID: | PMC148765 |
| DOI: | 10.1093/nar/27.24.4671 |
| DOI/URL: | |
| Notes: | Article -- Export Date: 16 August 2016 -- Source: Scopus |
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