Extended -10 motif is critical for activity of the cspA promoter but does not contribute to low-temperature transcription.
Bacterial promoters belonging to the extended -10 class contain a conserved TGn motif upstream of the -10 promoter consensus element. Open promoter complexes can be formed on some extended -10 Escherichia coli promoters at temperatures as low as 6 degrees C, when complexes on most promoters are closed. The promoter of cspA, a gene that codes for the major cold shock protein CspA of E. coli, contains an extended -10 motif. CspA is dramatically induced upon temperature downshift from 37 to 15 degrees C, and its cold shock induction has been attributed to transcription, translation, and mRNA stabilization effects. Here, we show that though the extended -10 motif is critical for high-level expression of cspA, it does not contribute to low-temperature expression. In fact, transcription from the wild-type cspA promoter is cold sensitive in vitro and in vivo. Thus, transcription appears to play little or no role in low-temperature induction of cspA expression.
Phadtare
Sangita
S
Department of Biochemistry, Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, New Jersey 08854, USA. phadtasa@umdnj.edu
Severinov
Konstantin
K
D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D003080:Cold Temperature; D004926:Escherichia coli / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000502:physiology*; D013696:Temperature; D014158:Transcription, Genetic
D001426:Bacterial Proteins; C062260:cold shock protein CS7.4, Bacteria