TY - JOUR
T1 - The cyanobacterial principal σ factor region 1.1 is involved in DNA-binding in the free form and in transcription activity as holoenzyme
AU - Imashimizu, Masahiko
AU - Hanaoka, Mitsumasa
AU - Seki, Asako
AU - Murakami, Katsuhiko S.
AU - Tanaka, Kan
N1 - Funding Information:
We thank Drs. S. Imamura, M. Asayama, and M. Shirai (Ibaraki University) for antisera to core RNAP of Synechocystis sp. PCC 6803, Dr. A. Ishihama (Hosei University) for E. coli σ 70 antibody, Drs. M. Iwai and M. Ikeuchi (University of Tokyo) for T. elongatus cells, and B.J. Klein and M.L. Gleghorn (Pennsylvania State University) for critical reading of the manuscript. This study was supported by a Grant-in-Aid for Creative Scientific Research (16GS0304) from the Ministry of Education, Culture, Sports, Science and Technology, Japan.
PY - 2006/6/12
Y1 - 2006/6/12
N2 - Cyanobacterial principal σ factor, σA, includes a specifically conserved cluster of basic amino acids in the amino-terminal extension called region 1.1. We found that the σA in a thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 binds DNA in the absence of the core RNA polymerase and that σA lacking region 1.1 is not able to bind DNA. This indicates that, in the cyanobacterium, region 1.1 participates in DNA-binding, rather than inhibiting the interaction between free σ and DNA, as found in other principal σ factors of eubacteria. The results of in vitro transcription assays with the reconstituted RNA polymerase showed that region 1.1 reduces transcription activity from the cpc promoter.
AB - Cyanobacterial principal σ factor, σA, includes a specifically conserved cluster of basic amino acids in the amino-terminal extension called region 1.1. We found that the σA in a thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 binds DNA in the absence of the core RNA polymerase and that σA lacking region 1.1 is not able to bind DNA. This indicates that, in the cyanobacterium, region 1.1 participates in DNA-binding, rather than inhibiting the interaction between free σ and DNA, as found in other principal σ factors of eubacteria. The results of in vitro transcription assays with the reconstituted RNA polymerase showed that region 1.1 reduces transcription activity from the cpc promoter.
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U2 - 10.1016/j.febslet.2006.05.017
DO - 10.1016/j.febslet.2006.05.017
M3 - Article
C2 - 16712841
AN - SCOPUS:33646930086
SN - 0014-5793
VL - 580
SP - 3439
EP - 3444
JO - FEBS Letters
JF - FEBS Letters
IS - 14
ER -