Abstract
A cDNA coding for GTP:α-D-mannose-1-phosphate guanyltransferase (MPG1 transferase) (EC 2.7.7.13) was isolated from a cDNA library of the Trichoderma reesei RutC-30 strain by suppression of the yeast Saccharomyces cerevisiae mutation in the DPM1 gene encoding mannosylphosphodolichol (MPD) synthase. The nucleotide sequence of the 1.6 kb-long cDNA revealed an ORF which encodes a protein of 364 amino acids. Sequence comparisons demonstrate 70% identity with the S. cerevisiae guanyl transferase gene (MPG1) and 75% identity with the Schizosaccharomyces pombe homologue. No similarity was found with the MPD synthase encoded by the S. cerevisiae DPM1 gene. The possibility that cloned cDNA encodes a product with a MPD synthase activity was also excluded by transforming a heterozygous S. cerevisiae dpm1::LEU2/DPM1 diploid, which did not lead to the restoration of viability of the dpm1 spores. Simultaneously, a significant increase in MPG transferase activity, as compared with the wild-type yeast, was observed in cellular extracts when the mpg1 cDNA from Trichoderma was expressed in the S. cerevisiae dpm1-6 mutant.
Original language | English |
---|---|
Pages (from-to) | 445-450 |
Number of pages | 6 |
Journal | Current Genetics |
Volume | 33 |
Issue number | 6 |
DOIs | |
Publication status | Published - 1 Jan 1998 |
MoE publication type | A1 Journal article-refereed |
Funding
Acknowledgements We are very grateful to Dr. Peter Orlean (Univ. of Illinois at Urbana, USA) for providing yeast strains and communicating unpublished results. We thank Ms. Riitta Nurmi (VTT Biotechnology and Food Research, Espoo, Finland) for technical assistance and Dr. Andrzej Migdalski (Institute of Biochemistry and Biophysics, Warsaw, Poland) for help in sequence analysis. The work was partially financed by The Committee for Scientific Research (KBN, Poland, Grant 6P04B 01712) and the exchange program between the Finnish and Polish Academies of Science. The GenBank accession number of the T. reesei mpg1 sequence is U89991.
Keywords
- dpm1 mutant
- Glycosylation
- GTP:α-D-mannose-1-phosphate guanyltransferase
- mpg1 gene
- S. cerevisiae
- Trichoderma reesei