Insertional inactivation of the gene encoding a 76-kilodalton cell surface polypeptide in Streptococcus gordonii Challis has a pleiotropic effect on cell surface composition and properties.
Infect Immun
; 58(11): 3689-97, 1990 Nov.
Article
em En
| MEDLINE
| ID: mdl-2228239
ABSTRACT
A library of Streptococcus gordonii DL1-Challis DNA was constructed in lambda gt11. Phage plaques were screened for production of antigens that reacted with antiserum to S. gordonii cell surface proteins. A recombinant phage denoted lambda gt11-cp2 was isolated that carried 1.85 kb of S. gordonii DNA and that expressed an antigen with a molecular mass of 29 kDa in Escherichia coli. Antibodies that reacted with the expression product were affinity purified and were shown to react with a single polypeptide antigen with a molecular mass of 76 kDa in S. gordonii DL1-Challis. A segment (0.85 kb) of the cloned DNA within the transcription unit was ligated into a nonreplicative plasmid carrying an erythromycin resistance determinant and transformed into S. gordonii DL1-Challis. The plasmid integrated onto the chromosome, and expression of the 76-kDa polypeptide antigen was abolished. The gene inactivation had no obvious effect on bacterial growth or on a number of phenotypic properties, including hydrophobicity and adherence. However, it abolished serum-induced cell aggregation, mutant cells had reduced aggregation titers in saliva and in colostrum immunoglobulin A, and it also reduced coaggregation with some Actinomyces species. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of cell envelope proteins from wild-type and mutant strains showed that as well as lacking the surface-exposed 76-kDa polypeptide, mutant cell envelopes were deficient in several other polypeptides, including those that bound to immunoglobulin A. Expression of the gene encoding the 76-kDa polypeptide in S. gordonii appeared to be critical for functional conformation of the cell surface.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Streptococcus
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Regulação da Expressão Gênica
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Proteínas de Membrana
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Mutação
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Antígenos de Superfície
Limite:
Animals
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Humans
Idioma:
En
Revista:
Infect Immun
Ano de publicação:
1990
Tipo de documento:
Article
País de afiliação:
Nova Zelândia
País de publicação:
EEUU
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ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA