Glycine betaine loses its osmoprotective activity in a bspA strain of Erwinia chrysanthemi

Citation
T. Touze et al., Glycine betaine loses its osmoprotective activity in a bspA strain of Erwinia chrysanthemi, MOL MICROB, 42(1), 2001, pp. 87-99
Citations number
49
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
MOLECULAR MICROBIOLOGY
ISSN journal
0950-382X → ACNP
Volume
42
Issue
1
Year of publication
2001
Pages
87 - 99
Database
ISI
SICI code
0950-382X(200110)42:1<87:GBLIOA>2.0.ZU;2-C
Abstract
Erwinia chrysanthemi insertion mutants were isolated that grew poorly speci fically in the presence of glycine betaine (GB) or its analogues in high-sa lt media. Transposon insertions were found to affect the bspA gene, which f orms an operon including the psd locus coding for phosphatidylserine decarb oxylase. Initial GB uptake is not affected by the bspA mutation. However, i n high-salt medium, its initial accumulation is followed by a reduced gluco se uptake and a release of GB but not a loss of viability. BspA is homologo us to the widespread MscS channel, YggB, but does not seem to constitute a mechanosensitive channel. We suggest that BspA is a protein sensing both in tracellular GB and the extracellular salt content of the medium, the hypoth esis being built on the observation that BspA is necessary to maintain the GB pool during osmoadaptation in high-salt media containing this osmoprotec tant.