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Cloning of a surface protein antigen gene from serotype c Streptococcus mutans
Author(s) -
Okahashi N.,
Sasakawa C.,
Yoshikawa M.,
Hamada S.,
Koga T.
Publication year - 1989
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1989.tb01811.x
Subject(s) - biology , plasmid , streptococcus mutans , microbiology and biotechnology , gene , mutant , escherichia coli , molecular cloning , sequence analysis , peptide sequence , genetics , bacteria
Summary The structural gene for a 190kD protein antigen (PAc) of Streptococcus mutans MT8148 (serotype c ) was cloned into the plasmid vector pUC118. SDS‐polyacrylamide gel electrophoresis and Western immunoblotting showed that the Escherichia coli harbouring the chimaeric plasmid produced multiple polypeptides of 190‐210kD. Immunodiffusion analysis revealed that the cloned PAc had the same specific determinants as S. mutans PAc. The cloned pac gene was mapped, and its transcriptional orientation was determined by characterizing deletion mutants of the chimaeric plasmid. Southern blot analysis with the cloned gene sequence as a probe revealed the presence of a homologous sequence in DNAs from sero‐types e and f S. mutans. PAc‐defective mutants were constructed by inserting an erythromycin‐resistance gene into the pac gene. The cell‐surface hydrophobicity of the mutants was lower than that of the parent strain.