title: Genomic organization of a polygalacturonase gene from a hyperpectinolytic mutant strain of Penicillium occitanis.
abstract: The pga1 gene encoding an endopolygalacturonase was isolated from a hyperpectinolytic mutant strain of Penicillium occitanis. It consists of an ORF of 1.155 kbp encoding a putative protein of 346 amino acids with a predicted molecular mass of 39 kDa, belonging to the family 28 of glycosyl hydrolases. The deduced amino acid sequence comprises a putative 38 N terminal amino acids of the prepropeptide. The nature and position of amino acids comprising the active site as well as the overall three-dimensional structure were well conserved between the P. occitanis pga1 and all polygalacturonases. The coding region of the pga1 gene is interrupted by three short introns of 57, 53 and 65 bp in length. In addition to the determination of the transcription start site, the promoter sequence from the pga1 gene was analysed. It showed the conservation of known response elements for CreA and Hap2-3-4 factors. Southern blot analysis at high stringency shows that the isolated polygalacturonase gene exists as a single copy in the fungus genome. Northern blot analysis confirmed the constitutive hyperpectinolytic nature of the hyperpectinolytic CT1 mutation as high levels of pga1 mRNA were observed either on pectin or on glucose-grown cells.
authors.affiliation: Laboratoire de Génétique Moléculaire des Eucaryotes, Centre de Biotechnologie de Sfax, Sfax, Tunisia.
authors.forename: Hèla
authors.initials: H
authors.lastname: Trigui-Lahiani
authors.forename: Malika
authors.initials: M
authors.lastname: Ayadi
authors.forename: Noomen
authors.initials: N
authors.lastname: Hadj-Taïeb
authors.forename: Mamdouh Ben
authors.initials: MB
authors.lastname: Ali
authors.forename: Ali
authors.initials: A
authors.lastname: Gargouri
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D015139:Blotting, Southern; D017124:Conserved Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D018628:Gene Dosage; D020869:Gene Expression Profiling; D005947:Glucose / Q000378:metabolism; D007438:Introns; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010368:Pectins / Q000378:metabolism; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics*; D011096:Polygalacturonase / Q000737:chemistry / Q000235:genetics*; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals; D012331:RNA, Fungal / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D024363:Transcription Initiation Site
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D021382:Protein Sorting Signals; D012331:RNA, Fungal; D012333:RNA, Messenger; D010368:Pectins; D011096:Polygalacturonase; D005947:Glucose