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Enzymes of the Rel/Spo family enable bacteria to survive prolonged periods of nutrient limitation by producing an intracellular signaling alarmone, (p)ppGpp, which triggers the so-called stringent response. Both the synthesis of (p)ppGpp from ATP and GDP(GTP), and its hydrolysis to GDP(GTP) and pyrophosphate, are catalyzed by Rel/Spo proteins. The 2.1 A(More)
The complete nucleotide sequences of four genes and one open reading frame (ORF1) adjacent to the streptokinase gene, skc, from Streptococcus equisimilis H46A were determined. These genes are encoded on the opposite DNA strand to skc and are arranged as follows: dexB-abc-lrp-skc-ORF1-rel. The dexB gene, coding for an alpha-glucosidase (M(r) 61,733), and(More)
In this investigation, we identify the CodY protein from Streptococcus pyogenes as a pleiotropic transcription regulator with global features. The notion that acquisition of nutrients by this polyauxotrophic organism is the primary event occurring during the establishment of infection and that virulence expression is a result of this quest, led us to study(More)
In an attempt to expand the available knowledge of pathogen-host interactions during ex vivo growth of Streptococcus pyogenes (GAS) in nonimmune whole human blood, the extents to which the expression of 51 genes including regulators with known targets, established virulence factors, physiologically important transporters and metabolic enzyme genes was(More)
  • H Malke
  • 1974
Of 5 clinically isolated strains of Streptococcus pyogenes, 3 showed high-level resistance to erythromycin and lincomycin that was inducible by subinhibitory concentrations of these drugs (IR strains) while 2 strains exhibited constitutive erythromycin and lincomycin resistance (CR strains) which was expressed without prior exposure to low drug(More)
The gene specifying the group A streptokinase (ska) gene was cloned from an M type 49 strain of Streptococcus pyogenes and shown to express in Escherichia coli. The nucleotide sequence of the DNA fragment carrying ska was determined and compared to that of the group C streptokinase gene (skc). There is 90% sequence identity between the two genes, with(More)
  • H Malke
  • 1986
Codon usage was analysed for 14 streptococcal genes or significant open reading frames and found to be different from that in Escherichia coli and Bacillus subtilis. In particular, the preferred use of WWT codons over WWC was inconsistent with the rule of optimal codon-anticodon interaction energy. On the other hand, for SSTC codons, adherence to this rule(More)
Control over mRNA stability is an essential part of gene regulation that involves both endo- and exoribonucleases. RNase Y is a recently identified endoribonuclease in Gram-positive bacteria, and an RNase Y ortholog has been identified in Streptococcus pyogenes (group A streptococcus [GAS]). In this study, we used microarray and Northern blot analyses to(More)
Streptococcus pyogenes (group A streptococcus [GAS]), a multiple-amino-acid-auxotrophic human pathogen, may face starvation for essential amino acids during various stages of the infection process. Since the response of GAS to such conditions is likely to influence pathogenetic processes, we set out to identify by transcriptional analyses genes and operons(More)
Considering that group A streptococci are multiple auxotrophs that may encounter shortage of amino acids during specific stages of the infectious process, we studied their adaptive response to amino acid deprivation. We found that, in addition to the (p)ppGpp-mediated stringent response characterized previously, Streptococcus pyogenes exhibits a(More)