[Construction of Streptococcus mutans luxS gene allelic exchange plasmid].
OBJECTIVE
It is reported that Streptococcus mutans luxS gene may have an important role in the interspecies quorum sensing system. To construct the S. mutans luxS gene knockout mutant, this research aim to construct the luxS gene allelic exchange plasmid.


METHODS
The upstream and downstream flank DNA fragments of S. mutans luxS gene (Xup, Xdn)and the E. coli kanamycin resistance gene (Kana) were enriched by pfu DNA polymerase with "nest PCR" methods. These fragments were ligated into pBluescript SK (+) Phagemids vector with double endonuclease reaction sequentially.


RESULTS
With endonuclease reaction and DNA sequencing, it was proved that the objective plasmid, Xukd-pbsk, was constructed correctively and the kanamycin resistance gene could be expressed in vitro.


CONCLUSIONS
The S. mutans luxS gene allelic exchange plasmid is constructed correctively in this research and can be used in the future research of S. mutans luxS gene knockout mutant.
Huang
Zheng-Wei
ZW
Dept. of Oral Medicine, The Ninth Affiliated Hospital of Shanghai Jiaotong University School of Medicine, Shanghai 200011, China.
Liu
Zheng
Z
D001426:Bacterial Proteins; D013437:Carbon-Sulfur Lyases; D004926:Escherichia coli; D005822:Genetic Vectors; D010957:Plasmids; D016133:Polymerase Chain Reaction; D053038:Quorum Sensing; D013295:Streptococcus mutans
D001426:Bacterial Proteins; D013437:Carbon-Sulfur Lyases