title: Characterisation and expression of a gene encoding a mutarotase from the fungus Rhizopus nigricans.
abstract: A gene coding for a mutarotase was isolated and characterised from the filamentous fungus Rhizopus nigricans. In order to determine the encoded enzyme's activity a recombinant protein was prepared in the baculovirus expression system and the mutarotase activity was determined. Expression studies showed that the gene is repressed by high as well as low concentrations of glucose and derepressed during deficiency of glucose. Besides the regulation at the level of transcription, an accelerative effect of glucose in growth medium on the mutarotase mRNA decay was also demonstrated. Moreover, a Southern hybridisation performed at lower temperatures suggested that the R. nigricans genome harbours a nucleotide sequence, that is homologous to the isolated gene.
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia.
authors.forename: Tanja
authors.initials: T
authors.lastname: Vilfan
authors.forename: Bronislava
authors.initials: B
authors.lastname: Cresnar
authors.forename: Didier
authors.initials: D
authors.lastname: Fournier
authors.forename: Jure
authors.initials: J
authors.lastname: Stojan
authors.forename: Katja
authors.initials: K
authors.lastname: Breskvar
mesh_terms: D001483:Base Sequence; D002238:Carbohydrate Epimerases / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D015971:Gene Expression Regulation, Enzymologic; D005800:Genes, Fungal; D005947:Glucose / Q000494:pharmacology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012233:Rhizopus / Q000201:enzymology* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D002238:Carbohydrate Epimerases; C019646:aldose 1-epimerase; D005947:Glucose