Existence of three regulatory regions each containing a highly conserved motif in the promoter of plastid-encoded RNA polymerase gene (rpoB).
The plastid gene rpoB encodes a plastid-specific, DNA-dependent RNA polymerase. A study of a barley mutant, albostrians, indicated that rpoB itself is transcribed by a nuclear-encoded RNA polymerase. However, the molecular nature of the nuclear-encoded RNA polymerase and mechanisms of the transcriptional regulation of rpoB expression have not been elucidated. Using an in vivo transient assay system for gene expression in plastids, the 5'-flanking region of rpoB from Arabidopsis thaliana in plastids of cultured BY-2 tobacco cells was analyzed. A series of deletion analyses of the 5'-flanking region indicated that there were two positive and one negative regulatory regions for rpoB expression. Comparison of the 5'-flanking sequences of rpoB among several plant species revealed the existence of three conserved motifs in these regions.
Inada
H
H
Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
Seki
M
M
Morikawa
H
H
Nishimura
M
M
Iba
K
K
D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D017343:Genes, Plant; D005809:Genes, Regulator; D005966:Glucuronidase / Q000235:genetics; D001467:Hordeum / Q000201:enzymology / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D018087:Plastids / Q000235:genetics; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics
D017931:DNA Primers; D018744:DNA, Plant; D010940:Plant Proteins; C101305:RpoB protein, Oryza sativa; D012321:DNA-Directed RNA Polymerases; D005966:Glucuronidase