Open AccessAn operator binding‐negative mutation of Xyl repressor from Bacillus subtilis is trans dominant in Bacillus megaterium
Author(s) -
Kauder Christine,
Allmansberger Rudolf,
Gärtner Dagmar,
Schmiedel Dagmar,
Hillen Wolfgang
Publication year - 1993
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.1574-6968.1993.tb06147.x
Subject(s) - repressor , bacillus subtilis , operon , bacillus megaterium , lac operon , biology , operator (biology) , mutation , genetics , microbiology and biotechnology , gene , plasmid , gene expression , escherichia coli , bacteria
We have selected a Bacillus subtilis 168‐borne xylR Ser to Leu mutation at position 41 of the encoded amino acid sequence showing a constitutive expression phenotype for the xyl operon. When cloned on a multi‐copy plasmid in a B. megaterium strain harbouring a single‐copy xylA‐lacZ fusion it leads to derepressor of β‐galactosidase expression. Thus, it is trans dominant over the endogenous xylR , indicating that Xyl repressor functions as a multimer. This result also supports the assumption that the mutation is in a putative α‐helix‐turn‐α‐helix operator binding motif of Xyl repressor.