Escherichia coli mutants deficient in the aspartate and aromatic amino acid aminotransferases

Aspartate taxis mutants of the Escherichia coli tar chemoreceptor.

The Tar protein of Escherichia coli belongs to a family of methyl-accepting inner membrane proteins that mediate chemotactic responses to a variety of compounds. These transmembrane signalers monitor the chemical environment by means of specific ligand-binding sites arrayed on the periplasmic side of the membrane, and in turn control cytoplasmic signals that modulate the flagellar rotational ma...

Characterization of Two Aromatic Amino Acid Aminotransferases and Production of Indoleacetic Acid in Azospirillum Strains

Sunnnary-Experiments were made to quantify indole-3-acetic acid (IAA) excreted by different wild type strains of Azospirilhun spp. The microorganisms produce IAA, during the late stationary growth phase and show a significant increase in IAA production when tryptophan is present in the medium. Under these conditions with the A. brusilense strain UAP 14, we observed two aromatic amino acid amino...

The amino acid pool in Escherichia coli.

Thymineless death in recombination deficient mutants of Escherichia coli K12.

When grown in thymine-free minimal synthetic medium, thyA recA mutants of Escherichia coli K12 were comparatively more resistant and thyA recBC mutants more sensitive to thymineless death (TLD) than their respective parent strains. No excessive numbers of single-strand breaks were observed in the DNA of the recBC mutant strain starved for thymine, hence the hypersensitivity for TLD in this stra...

Screening procedure for Escherichia coli mutants deficient in ribonuclease I.

Strains of Escherichia coli that possess ribonucleic acid accumulated under relaxed growth conditions show a considerable increase in time before the onset of beta-galactosidase inducibility. This time dependency can be related to the presence or absence of ribonuclease I.