HrcA is a negative regulator of the dnaK and groESL operons of Streptococcus pyogenes.
The genome of Streptococcus pyogenes, an important human pathogen, encodes homologs of the principal bacterial heat shock proteins DnaK and GroES, -EL, as well as HrcA, a negative regulator of dnaK and groESL expression in other Gram-positive bacteria. Using nuclease protection assays to measure dnaK/groESL mRNA abundance and a "non-polar" insertion to disrupt hrcA, we demonstrate that heat shock triggers a 4- to 8-fold increase in dnaK and groESL-specific mRNAs within 5 min of the temperature shift and that HrcA is a negative regulator of S. pyogenes dnaK/groESL mRNA abundance in unstressed S. pyogenes. Although the loss of HrcA elevated dnaK and groESL mRNA levels under non-heat shock conditions, the relative abundance of these RNAs increased further in heat shocked S. pyogenes, suggesting an additional element contributing to their synthesis or stability.
Woodbury
Robyn
R
Department of Microbiology and Immunology MC7758, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229-3900, USA.
Haldenwang
W G
WG
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018833:Chaperonins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009876:Operon; D012329:RNA, Bacterial / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D013297:Streptococcus pyogenes / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C097970:GroESL protein, Bacteria; D018840:HSP70 Heat-Shock Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012097:Repressor Proteins; D018833:Chaperonins; C063842:dnaK protein, E coli