Open AccessEvolutionary origin of the R hodobacter sphaeroides specialized RpoN sigma factors
Author(s) -
Domenzain Clelia,
Camarena Laura,
Osorio Aurora,
Dreyfus Georges,
Poggio Sebastian
Publication year - 2012
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.1574-6968.2011.02459.x
Subject(s) - rpon , rhodobacter sphaeroides , biology , sigma factor , genetics , gene , gene duplication , rhodobacter , gene cassette , plasmid , mutant , gene expression , bacteria , promoter , integron
Gene duplication and horizontal gene transfer (HGT) are two events that enable the generation of new genes. R hodobacter sphaeroides ( WS 8 and 2.4.1 strains) has four copies of the rpoN gene that are not functionally interchangeable. Until now, this is the only example of specialization of this sigma factor. In this work, we aimed to determine whether the multiple copies of this gene originated from HGT or through gene duplication. Our results suggest a multiplication origin of the different rpoN copies that occurred after the R hodobacter clade separated. Functional tests indicate that the specialization of the rpoN genes is not restricted to R . sphaeroides . We propose that the rpoN copy involved in nitrogen fixation is the ancestral gene and that the other rpoN genes have acquired new specificities.