Two proline porters in Escherichia coli K-12.
AUTOR(ES)
Stalmach, M E
RESUMO
Escherichia coli mutants defective at putP and putA lack proline transport via proline porter I and proline dehydrogenase activity, respectively. They retain a proline uptake system (proline porter II) that is induced during tryptophan-limited growth and are sensitive to the toxic L-proline analog, 3,4-dehydroproline. 3,4-Dehydroproline-resistant mutants derived from a putP putA mutant lack proline porter II. Auxotrophic derivatives derived from putP+ or putP bacteria can grow if provided with proline at low concentration (25 microM); those derived from the 3,4-dehydroproline-resistant mutants require high proline for growth (2.5 mM). We conclude that E. coli, like Salmonella typhimurium, possesses a second proline porter that is inactivated by mutations at the proP locus.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=217857Documentos Relacionados
- Proline transport and osmotic stress response in Escherichia coli K-12.
- Origins of the osmoprotective properties of betaine and proline in Escherichia coli K-12.
- Cadmium uptake in Escherichia coli K-12.
- Cloning and expression of two Streptococcus mutans glucosyltransferases in Escherichia coli K-12.
- Two fep genes are required for ferrienterochelin uptake in Escherichia coli K-12.