Open AccessTwo forms of DNA‐dependent RNA polymerase α subunit in streptomycetes
Author(s) -
Najmanová Lucie,
Janata Jiří,
Kalousek František,
Novák Petr,
Felsberg Jürgen,
Spížek Jaroslav
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb09128.x
Subject(s) - rna polymerase , protein subunit , biology , specificity factor , transcription (linguistics) , microbiology and biotechnology , dna , streptomyces , gene , g alpha subunit , polymerase , escherichia coli , biochemistry , genetics , bacteria , linguistics , philosophy
We demonstrated two different DNA‐dependent RNA polymerase (RNAP) α subunits in spores of Streptomyces granaticolor with apparent molecular masses of 40 and 43 kDa. The 43‐kDa subunit was also found in vegetative cells. These two proteins are highly similar to each other as well as to other bacterial RNAP α subunits. The 40‐kDa subunit is shortened from its C‐terminus, in the portion of the protein, required for binding of DNA and transcription regulators. The gene for RNAP α from S. granaticolor was cloned and sequenced and the corresponding protein was overproduced in Escherichia coli . In vitro experiments using purified RNAP α showed that the cell free extract from spores of S. granaticolor exhibits proteolytic activity responsible for the α subunit shortening, whereas that from vegetative cells does not. This modification of α subunit might point to a novel mechanism of transcriptional control in streptomycetes.