title: Identification and characterization of PaMTH1, a putative O-methyltransferase accumulating during senescence of Podospora anserina cultures.
abstract: A differential protein display screen resulted in the identification of a 27-kDa protein which strongly accumulates during the senescence of Podospora anserina cultures grown under standard conditions. After partial determination of the amino-acid sequence by mass-spectrometry analysis of trypsin-generated fragments, pairs of degenerated primers were deduced and used to amplify parts of the sequence coding for the protein. These PCR products were utilized to select specific cDNA and genomic clones from DNA libraries of P. anserina. A subsequent DNA-sequence analysis revealed that the 27-kDa protein is encoded by a discontinuous gene, PaMth1, capable of coding for 240 amino acids. The first three amino-terminal residues appear to be removed post-translationally. The deduced amino-acid sequence shows significant homology to S-adenosylmethionine (SAM)-dependent methyltransferases. We hypothesize that the 27-kDa protein, PaMTH1, is involved in age-related methylation reactions protecting aging cultures against increasing oxidative stress.
authors.affiliation: Molekulare Entwicklungsbiologie und Biotechnologie, Johann Wolfgang Goethe-Universität, Botanisches Institut, Frankfurt am Main, Germany.
authors.forename: N B
authors.initials: NB
authors.lastname: Averbeck
authors.forename: O N
authors.initials: ON
authors.lastname: Jensen
authors.forename: M
authors.initials: M
authors.lastname: Mann
authors.forename: H
authors.initials: H
authors.lastname: Schägger
authors.forename: H D
authors.initials: HD
authors.lastname: Osiewacz
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005800:Genes, Fungal / Q000235:genetics; D007438:Introns; D008780:Methyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D008780:Methyltransferases; C409687:PaMTH1 protein, Podospora anserina