The Plant Cell, Vol. 15, 195-205,
January 2003, Copyright © 2003,
American Society of Plant Biologists
Unique Architecture of the Plastid Ribosomal RNA Operon Promoter Recognized by the Multisubunit RNA Polymerase in Tobacco and Other Higher Plants
Jon Y. Suzuki,
Priya Sriraman1,
Zora Svab and
Pal Maliga2
Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8020
2 To whom correspondence should be addressed. E-mail maliga{at}waksman.rutgers.edu; fax 732-445-5735
Expression of the plastid rRNA operon (rrn) during development is highly regulated at the level of transcription. The plastid rrn operon in most higher plants is transcribed by the plastid-encoded RNA polymerase (PEP), the multisubunit plastid RNA polymerase from PrrnP1, a 70-type promoter with conserved -10 and -35 core promoter elements. To identify functionally important sequences, the tobacco PrrnP1 was dissected in vivo and in vitro. Based on in vivo deletion analysis, sequences upstream of nucleotide -83 do not significantly contribute to promoter function. The in vitro analyses identified an essential hexameric sequence upstream of the -35 element (GTGGGA; the rRNA operon upstream activator [RUA]) that is conserved in monocot and dicot species and suggested that the -10 element plays only a limited role in PrrnP1 recognition. Mutations in the initial transcribed sequence (+9 to +14) enhanced transcription, the characteristic of strong promoters in prokaryotes. We propose that interaction with the -10 element in PrrnP1 is replaced in part by direct PEP-RUA (proteinDNA) interaction or by proteinprotein interaction between the PEP and an RUA binding transcription factor.
This article has been cited by other articles:

|
 |

|
 |
 
K. A. Lutz, A. K. Azhagiri, T. Tungsuchat-Huang, and P. Maliga
A Guide to Choosing Vectors for Transformation of the Plastid Genome of Higher Plants
Plant Physiology,
December 1, 2007;
145(4):
1201 - 1210.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Courtois, L. Merendino, E. Demarsy, R. Mache, and S. Lerbs-Mache
Phage-Type RNA Polymerase RPOTmp Transcribes the rrn Operon from the PC Promoter at Early Developmental Stages in Arabidopsis
Plant Physiology,
November 1, 2007;
145(3):
712 - 721.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|