title: Isolation, sequencing and expression of cDNA sequences encoding uroporphyrinogen decarboxylase from tobacco and barley.
abstract: We have cloned and sequenced a full-length cDNA for uroporphyrinogen decarboxylase (UROD, EC 4.1.1.37) from tobacco (Nicotiana tabacum L.) and a partial cDNA clone from barley (Hordeum vulgare L.). The cDNA of tobacco encodes a protein of 43 kDa, which has 33% overall similarity to UROD sequences determined from other organisms. We propose that tobacco UROD has an N-terminal extension of 39 amino acid residues. This extension is most likely a chloroplast transit sequence. The in vitro translation product of UROD was imported into pea chloroplasts and processed to ca. 39 kDa. A truncated cDNA, from which the putative transit peptide had been deleted, was used to over-express the mature UROD in Escherichia coli. Purified protein showed UROD activity, thus providing an adequate source for subsequent enzymatic characterization and inhibition studies. Expression of UROD was investigated by northern and western blot analysis during greening of etiolated barley seedlings, and in segments of barley primary leaves grown under day/night cycles. The amount of RNA and protein increased during illumination. Maximum UROD-RNA levels were detected in the basal segments relative to the top of the leaf.
authors.affiliation: Institute of plant genetics and crop plant research, Gatersleben, Germany.
authors.forename: H P
authors.initials: HP
authors.lastname: Mock
authors.forename: L
authors.initials: L
authors.lastname: Trainotti
authors.forename: E
authors.initials: E
authors.lastname: Kruse
authors.forename: B
authors.initials: B
authors.lastname: Grimm
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D015152:Blotting, Northern; D015153:Blotting, Western; D002736:Chloroplasts / Q000201:enzymology / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015723:Gene Library; D001467:Hordeum / Q000201:enzymology / Q000235:genetics* / Q000528:radiation effects; D008027:Light; D008969:Molecular Sequence Data; D010947:Plants, Toxic; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*; D014575:Uroporphyrinogen Decarboxylase / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification
chemical_list: D018076:DNA, Complementary; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014575:Uroporphyrinogen Decarboxylase