A promoter switch that can rescue a plant sigma factor mutant.
Chloroplasts sigma factors act in concert with PEP, the bacterial-type plastid RNA polymerase. Using a sigma knockout line from Arabidopsis thaliana, we investigated mutant-specific changes in plastid gene expression at RNA level. One characteristic feature was the appearance of a long transcript that spans the atpB-E operon and extends considerably into the far-upstream region of atpB. This region reveals a cluster of typical promoter elements for NEP, the second (phage-type) plastid RNA polymerase. The NEP promoter cluster can help maintain RNA synthesis in situations where no functional sigma factor is available for PEP.
Schweer
Jennifer
J
Plant Cell Physiology and Molecular Biology, ND 2/72, University of Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany.
Loschelder
Heike
H
Link
Gerhard
G
D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D018742:DNA, Chloroplast / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D008957:Models, Genetic; D008969:Molecular Sequence Data; D008970:Molecular Weight; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics*
D029681:Arabidopsis Proteins; D018742:DNA, Chloroplast; D050505:Mutant Proteins; D012333:RNA, Messenger; D012808:Sigma Factor; D012321:DNA-Directed RNA Polymerases