Open AccessCharacterization of a methionine sulfoximine resistant strain of Rhodobacter capsulatus E1F1
Author(s) -
Romero Francisco,
Quintero Antonio,
Roldán JoséManuel
Publication year - 1989
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1989.tb03579.x
Subject(s) - rhodobacter , asparagine , glutamine , biochemistry , mutant , glutamine synthetase , alanine , cysteine , methionine , biology , non competitive inhibition , serine , leucine , amino acid , enzyme , gene
A mutant strain of Rhodobacter capsulatus E1 F1 able to grow in the presence of the specific inhibitor l ‐methionine‐ d,l ‐sulfoximine (MSX) has been characterized. The mutant appears to possess an altered MSX transport system. Both, parental and mutant strains showed identical glutamine synthetase (GS) activity and intracellular enzyme levels. Besides, the enzymes from both sources were inactivated in vitro by MSX with a similar rate and presented antigenic identity. On the basis of growth experiments in different nitrogen sources and transport competition tests, we propose that some amino acids (cysteine, serine, leucine, asparagine, glutamate and glutamine) could share a common carrier with MSX. Alanine appears to act as a non competitive inhibitor of mSX transport in R. capsulatus .