Temperature-sensitive murein synthesis in an Escherichia coli pdx mutant and the role of alanine racemase.

Abstract

The basis for disruption of morphogenesis by depletion of pyridoxine derivatives was studied using a pdxH null mutant of Escherichia coli K-12. Removal of pyridoxal from growing cultures severely inhibited murein synthesis in vivo, whereas simultaneous supplementation with D-alanine effectively prevented inhibition. Extractable alanine racemase was low following such starvation. Selection of mutants overcoming the glycine- or temperature-sensitivity imposed by pyridoxine limitation yielded a variety of phenotypes. The most effective of these extragenic suppressors conferred an elevated alanine racemase activity which was resistant to the effects of pyridoxal removal.

• Authors: D W Grogan
• Journal: Archives of microbiology (Arch Microbiol) Vol. 150 Issue 4 Pg. 363-7 ( 1988) ISSN: 0302-8933 [Print] Germany
• PMID: 3060037 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Peptidoglycan
• Pyridoxal
• Amino Acid Isomerases
• Alanine Racemase
• Pyridoxine
• Alanine

Topics

• Alanine (metabolism)
• Alanine Racemase (metabolism)
• Amino Acid Isomerases (metabolism)
• Escherichia coli (genetics, growth & development, metabolism)
• Mutation
• Peptidoglycan (biosynthesis)
• Pyridoxal (metabolism)
• Pyridoxine (metabolism)
• Suppression, Genetic
• Temperature