ISOLATION, SEQUENCING AND EXPRESSION OF CDNA SEQUENCES ENCODING UROPORPHYRINOGEN DECARBOXYLASE FROM TOBACCO AND BARLEY

Citation
Hp. Mock et al., ISOLATION, SEQUENCING AND EXPRESSION OF CDNA SEQUENCES ENCODING UROPORPHYRINOGEN DECARBOXYLASE FROM TOBACCO AND BARLEY, Plant molecular biology, 28(2), 1995, pp. 245-256
Citations number
58
Categorie Soggetti
Plant Sciences",Biology
Journal title
ISSN journal
01674412
Volume
28
Issue
2
Year of publication
1995
Pages
245 - 256
Database
ISI
SICI code
0167-4412(1995)28:2<245:ISAEOC>2.0.ZU;2-9
Abstract
We have cloned and sequenced a full-length cDNA for uroporphyrinogen d ecarboxylase (UROD, EC 4.1.1.37) from tobacco (Nicotiana tabacum L.) a nd 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 tob acco 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 pro cessed to ca. 39 kDa. A truncated cDNA, from which the putative transi t peptide had been deleted, was used to over-express the mature UROD i n Escherichia coli. Purified protein showed UROD activity, thus provid ing an adequate source for subsequent enzymatic characterization and i nhibition 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 to p of the leaf.