ORAL STREPTOCOCCI WITH GENETIC-DETERMINANTS SIMILAR TO THE GLUCOSYLTRANSFERASE REGULATORY GENE, RGG

The Streptococcus gordonii Challis glucosyltransferase structural gene , gtfG, is positively regulated by the upstream gene, rgg, the only de scribed gtf regulatory determinant in oral streptococci. Southern hybr idization analyses indicated that rgg-like and gtfG-like determinants, were present on the same HindIII fragment in strains of S. gordonii, S treptococcus sanguis, and Streptococcus oralis, whereas no rgg-like de terminants,were detected in mutans streptococci, Streptococcus mitis, and Streptococcus salivarius.