[Effect of rpoS mutation on two gene clusters of phenazine in Psedomonas aeruginosa PAO1].
OBJECTIVE
As an opportunistic pathogen, Pseudomonas aeruginosa PAO1 can produce phenazine and its derivatives, which play a critical role in their pathogenesis. In many bacteria, RpoS, the product of rpoS gene, mediates biosynthesis of a set of secondary metabolites.


OBJECTIVE
This study aims to elucidate rpoS gene's function and regulation on two phenazine gene clusters in Pseudomonas aeruginosa PAO1.


METHODS
The rpoS gene and its upstream and downstream fragments were cloned from the chromosome of Pseudomonas aeruginosa. With the insertion of gentamycin resistance cassette (aacC1), the mutant PA-SG has been created by homologous recombination. Translational fusion plasmids phz1'-'lacZ (pMEZ1) and phz2'-'lacZ (pMEZ2) were constructed, and then were introduced into the wild type strain PAO1 and the mutant PA-SG, respectively. Activities of beta-galactosidase in them were determined with Miller method.


RESULTS
In KMB or PPM medium, beta-galactosidase activity of phzl'-'lacZ in the mutant PA-SG is much more than that in the wild type strain. However, beta-galactosidase activity of phz2'-'lacZ in the wild type strain is 2 -3 folds more than that in the mutant PA-SG.


CONCLUSIONS
With these results, it is suggested that regulation mediated by rpoS gene on two phenazine loci is specific and different.
Zhou
Jinfeng
J
School of Life Sciences, Ludong University, Yantai 264000, China. zjf12601260@126.com
Ge
Yihe
Y
Liu
Ting
T
Cheng
Xianhao
X
Wang
Lei
L
Gao
Xingxi
X
D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D005810:Multigene Family / Q000235:genetics*; D009154:Mutation; D010619:Phenazines / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000378:metabolism*; D012808:Sigma Factor / Q000235:genetics / Q000502:physiology*
D001426:Bacterial Proteins; D010619:Phenazines; C098602:PhzI protein, Pseudomonas sp.; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria