An operator binding-negative mutation of Xyl repressor from Bacillus subtilis is trans dominant in Bacillus megaterium.
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 derepression of beta-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 alpha-helix-turn-alpha-helix operator binding motif of Xyl repressor.
Kauder
C
C
Lehrstuhl für Mikrobiologie, Friedrich-Alexander Universität Erlangen-Nürnberg, FRG.
Allmansberger
R
R
Gärtner
D
D
Schmiedel
D
D
Hillen
W
W
D000595:Amino Acid Sequence; D001410:Bacillus megaterium / Q000235:genetics*; D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D015870:Gene Expression; D005799:Genes, Dominant; D008969:Molecular Sequence Data; D009154:Mutation; D009875:Operator Regions, Genetic; D010957:Plasmids / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D012097:Repressor Proteins; C074580:Xyl repressor protein, Bacillus subtilis