title: DNA gyrase, CS7.4, and the cold shock response in Escherichia coli.
abstract: We identify the A subunit of DNA gyrase as a cold shock protein whose synthesis is sustained following transfer of exponentially growing cultures of Escherichia coli from 37 to 10 degrees C. After a lag period in which its synthetic rate declines, synthesis of the A subunit of DNA gyrase increases relative to that of total protein. The duration of the lag period in synthesis and the synthetic rate of the A subunit appear dependent on the synthesis of a rapidly induced cold shock protein, CS7.4. The promoter of the gyrA gene contains specific binding sites for the CS7.4 protein, suggesting that CS7.4 acts at the transcriptional level to facilitate continued A-subunit synthesis. As synthesis of the B subunit of DNA gyrase is also sustained during cold shock, we suggest that an increase in the amount of DNA gyrase per cell might occur, which would potentially adapt the cells for growth at reduced temperatures (10 degrees C).
authors.affiliation: Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
authors.forename: P G
authors.initials: PG
authors.lastname: Jones
authors.forename: R
authors.initials: R
authors.lastname: Krah
authors.forename: S R
authors.initials: SR
authors.lastname: Tafuri
authors.forename: A P
authors.initials: AP
authors.lastname: Wolffe
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D001483:Base Sequence; D003080:Cold Temperature; D004250:DNA Topoisomerases, Type II / Q000096:biosynthesis*; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors; C062260:cold shock protein CS7.4, Bacteria; D004250:DNA Topoisomerases, Type II