RRC ID 3205
Author Hitomi M, Nishimura H, Tsujimoto Y, Matsui H, Watanabe K.
Title Identification of a helix-turn-helix motif of Bacillus thermoglucosidasius HrcA essential for binding to the CIRCE element and thermostability of the HrcA-CIRCE complex, indicating a role as a thermosensor.
Journal J Bacteriol
Abstract In the heat shock response of bacillary cells, HrcA repressor proteins negatively control the expression of the major heat shock genes, the groE and dnaK operons, by binding the CIRCE (controlling inverted repeat of chaperone expression) element. Studies on two critical but yet unresolved issues related to the structure and function of HrcA were performed using mainly the HrcA from the obligate thermophile Bacillus thermoglucosidasius KP1006. These two critical issues are (i) identifying the region at which HrcA binds to the CIRCE element and (ii) determining whether HrcA can play the role of a thermosensor. We identified the position of a helix-turn-helix (HTH) motif in B. thermoglucosidasius HrcA, which is typical of DNA-binding proteins, and indicated that two residues in the HTH motif are crucial for the binding of HrcA to the CIRCE element. Furthermore, we compared the thermostabilities of the HrcA-CIRCE complexes derived from Bacillus subtilis and B. thermoglucosidasius, which grow at vastly different ranges of temperature. The thermostability profiles of their HrcA-CIRCE complexes were quite consistent with the difference in the growth temperatures of B. thermoglucosidasius and B. subtilis and, thus, suggested that HrcA can function as a thermosensor to detect temperature changes in cells.
Volume 185(1)
Pages 381-5
Published 2003-1-1
DOI 10.1128/jb.185.1.381-385.2003
PMID 12486078
PMC PMC141899
MeSH Amino Acid Sequence Bacillus / chemistry Bacillus / genetics Bacillus / metabolism* Bacterial Proteins / chemistry Bacterial Proteins / metabolism Chaperonins DNA, Bacterial / metabolism* DNA-Binding Proteins Escherichia coli Proteins* HSP70 Heat-Shock Proteins / chemistry HSP70 Heat-Shock Proteins / metabolism Heat-Shock Proteins / chemistry Heat-Shock Proteins / metabolism Heat-Shock Response Helix-Turn-Helix Motifs* Molecular Sequence Data Protein Denaturation Repetitive Sequences, Nucleic Acid / genetics* Repressor Proteins / chemistry* Repressor Proteins / genetics Repressor Proteins / metabolism Temperature
IF 3.234
Times Cited 16
Prokaryotes E. coli ME9042(BL21(DE3))?