Histidine utilisation operon (hut) is upregulated at low temperature in the antarctic psychrotrophic bacterium Pseudomonas syringae
The antarctic psychrotrophic bacterium Pseudomonas syringae was mutagenised using a transposon Tn 5 -OT182 which facilitates identification of promoter fusions expressing the reporter gene ( lacZ ) for β-galactosidase. Most mutants expressed β-galactosidase both at optimal growth temperature (20–22°...
Published in: | FEMS Microbiology Letters |
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Main Authors: | , , , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
1998
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Subjects: | |
Online Access: | http://femsle.oxfordjournals.org/cgi/content/short/161/1/7 https://doi.org/10.1111/j.1574-6968.1998.tb12922.x |
Summary: | The antarctic psychrotrophic bacterium Pseudomonas syringae was mutagenised using a transposon Tn 5 -OT182 which facilitates identification of promoter fusions expressing the reporter gene ( lacZ ) for β-galactosidase. Most mutants expressed β-galactosidase both at optimal growth temperature (20–22°C) and at low temperature (4°C). But a small percentage of the mutants (∼5%) were unique in that they expressed β-galactosidase activity predominantly at low temperature. One such mutant was found to have an insertion in the gene for urocanase ( hutU ) of the histidine utilisation ( hut ) operon. Direct assay of urocanase and histidase activity in wild-type cells of various antarctic psychrotrophic strains including P. syringae, P. fluorescens and P. putida also suggested that the hut operon is expressed at an elevated level at low temperature. |
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