[Negative regulation on PCA production is not correlated with positive regulation on BHL and HHL synthesis by gacA in Pseudomonas sp. M18].
At least 5 kinds of N-acyl-homoserine lactones(AHLs) were identified in Pseudomonas sp. M18. They were: N-butyryl-L-homoserine lactone(C4-HSL, BHL), N-hexanoyl-L-homoserine lactone(C6-HSL, HHL), N-(3-oxohexanoyl)-L-homoserine lactone(3-Oxo-C6-HSL, OHHL), N-(3-oxooctanoyl)-L-homoserine lactone (3-Oxo-C8-HSL, OOHL) and N-(3-oxodecanoyl)-L-homoserine lactone(3-Oxo-C10-HSL, ODHL). Compared with the wide-type strain M18, the variety of the AHLs in the gacA mutant strain M18G reduced to 4 species with the decreased quantity. But the phenazine-1-carboxylic acid (PCA) production was increased by about 2-fold. The product of rhll plays an important role in synthesizing BHL and HHL. The rhll'-'lacZ translational fusion expression plasmid pMEIZ was constructed in vector pME6015 and then was introduced into the wild-type strain M18 and the gacA mutant strain M18G. The galactosidase activity in chromosomal gacA disruption mutant was only 60% of that in the wild-type strain M18. This result suggested that GacA could regulate the rhll expression positively. There was no influence on PCA production by adding exogenous BHL and HHL and both together to the culture of strains M18 and M18G. This result suggested that there was no relation between GacA's negative regulation on PCA production and positive regulation on BHL and HHL synthesis.
Tang
Xiang-Yong
XY
School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China. tangxiayon@yahoo.com.cn
Yan
An
A
Huang
Xian-Qing
XQ
Zhang
Xue-Hong
XH
Xu
Yu-Quan
YQ
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000494:pharmacology; D054742:Acyl-Butyrolactones / Q000032:analysis / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D015536:Down-Regulation; D007763:Lac Operon; D008025:Ligases / Q000235:genetics; D010619:Phenazines / Q000378:metabolism; D014176:Protein Biosynthesis; D011549:Pseudomonas / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D054742:Acyl-Butyrolactones; D001426:Bacterial Proteins; C091100:GacA protein, Bacteria; C092312:N-butyrylhomoserine lactone; C104908:N-hexanoyl-L-homoserine lactone; D010619:Phenazines; C037165:1-phenazinecarboxylic acid; D008025:Ligases; D015107:4-Butyrolactone