Open AccessIsolation and cloning of a Azospirillum lipoferum locus that complements Escherichia coli proU mutant
Author(s) -
Tripathi Anil Kumar,
Mishra Bal Mukund
Publication year - 1998
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.1574-6968.1998.tb13005.x
Subject(s) - betaine , complementation , mutant , escherichia coli , biochemistry , microbiology and biotechnology , biology , cosmid , recombinant dna , chemistry , gene
Glycine betaine relieved sodium chloride‐mediated inhibition of growth in Azospirillum lipoferum ATCC 29708. 35 S‐methionine labelling of proteins after salinity up‐shock revealed strong induction of a 30 kDa protein which cross‐reacted with the anti‐glycine betaine binding protein antibody from Escherichia coli . This suggested that A. lipoferum had a salinity‐induced ProU‐like high‐affinity glycine betaine transport system. A genomic library of A. lipoferum ATCC 29708 was screened for the proU ‐like gene by complementation of a proU mutant of E. coli . Four recombinant cosmids, capable of restoring growth of the proU mutant on plates containing 600 mM NaCl and 1 mM glycine betaine were selected. Selected recombinant cosmids hybridized with a proU gene probe from E. coli . Complementation of E. coli proU mutant with the A. lipoferum genomic DNA was evident by the ability of proU mutant (containing selected recombinant cosmids) to grow on minimal medium supplemented with 600 mM NaCl and 1 mM glycine betaine.