Regulation of aromatic amino acid biosynthesis in Escherichia coli K-12: control of the aroF-tyrA operon in the absence of repression control.

Abstract

Evidence was found which indicated that a mutation in gene trpS affected the rate of synthesis of tyrosine-repressible 3-deoxy-D-arabinoheptulosonic acid-7-phosphate (DAHP) synthetase. The effect was found to occur independently of repression mediated by the tyrR gene product, and it was not due to a change in growth rate, nor was it a manifestation of the stringent response. It is proposed that in the proximal region of the aroF-tyrA operon there is an attenuator site controlled by the level of charged tryptophanyl-transfer RNA. In addition, it was demonstrated that starvation for certain amino acids led to degradation of tyrosine-repressible DAHP synthetase, but not phenylalanine-repressible DAHP synthetase, and supplementation with the missing amino acid led to an increased rate of synthesis of tyrosine-repressible DAHP synthetase during subsequent growth.

• Authors: H Camakaris, J Camakaris, J Pittard
• Journal: Journal of bacteriology (J Bacteriol) Vol. 143 Issue 2 Pg. 613-20 (Aug 1980) ISSN: 0021-9193 [Print] United States
• PMID: 6782075 (Publication Type: Journal Article)

Chemical References

• Amino Acids
• Ketoses
• Sugar Phosphates
• 3-deoxy-D-arabino-heptulosonate-7-phosphate
• Tyrosine
• Phenylalanine
• Tryptophan
• GTP Pyrophosphokinase

Topics

• Amino Acids (biosynthesis)
• Enzyme Repression (drug effects)
• Escherichia coli (genetics)
• GTP Pyrophosphokinase (genetics)
• Ketoses (genetics)
• Operon
• Phenylalanine (pharmacology)
• Sugar Phosphates (genetics)
• Tryptophan (biosynthesis, genetics)
• Tyrosine (biosynthesis, pharmacology)