Molecular characterization and expression of the cell-associated glucosyltransferase gene from Streptococcus mutans.
A gene encoding cell-associated glucosyltransferase (CA-GTase) was cloned from Streptococcus mutans MT8148 into Escherichia coli DH5 alpha by using a low-copy-number plasmid, pMW119. After screening of a gene library with the oligonucleotide probe designed on the basis of a partial amino acid sequence of CA-GTase, a recombinant plasmid, pSK6, that had a 5.6 kb insert carrying the CA-GTase gene was selected. The gene product (recombinant CA-GTase) of pSK6 was expressed by using a lac promoter in pMW119. Western blotting revealed that rCA-GTase reacted with antibody to CA-GTase. rCA-GTase was found to synthesize water-insoluble glucans. Southern blotting indicated that the MT8148 chromosome contained another gene which was homologous to pSK6. A plasmid harboring this gene (pSK16) was also isolated from the gene library, the gene product of pSK16 exhibited GTase activity but ten times lower than that of pSK6.
Fujiwara
T
T
Department of Oral Microbiology, Osaka University Faculty of Dentistry, Japan.
Kawabata
S
S
Hamada
S
S
D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D005964:Glucosyltransferases / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D013295:Streptococcus mutans / Q000235:genetics*
D004269:DNA, Bacterial; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D005964:Glucosyltransferases