Three glycosylated serine-rich repeat proteins play a pivotal role in adhesion and colonization of the pioneer commensal bacterium, Streptococcus salivarius.
Environ Microbiol
; 19(9): 3579-3594, 2017 09.
Article
em En
| MEDLINE
| ID: mdl-28695648
ABSTRACT
Bacterial adhesion is a critical step for colonization of the host. The pioneer colonizer and commensal bacterium of the human gastrointestinal tract, Streptococcus salivarius, has strong adhesive properties but the molecular determinants of this adhesion remain uncharacterized. Serine-rich repeat (SRR) glycoproteins are a family of adhesins that fulfil an important role in adhesion. In general, Gram-positive bacterial genomes have a unique SRR glycoprotein-encoding gene. We demonstrate that S. salivarius expresses three large and glycosylated surface-exposed proteins - SrpA, SrpB and SrpC - that show characteristics of SRR glycoproteins and are secreted through the accessory SecA2/Y2 system. Two glycosyltransferases - GtfE/F - encoded outside of the secA2/Y2 locus, unusually, perform the first step of the sequential glycosylation process, which is crucial for SRR activity. We show that SrpB and SrpC play complementary adhesive roles involved in several steps of the colonization process auto-aggregation, biofilm formation and adhesion to a variety of host epithelial cells and components. We also show that at least one of the S. salivarius SRR glycoproteins is important for colonization in mice. SrpA, SrpB and SrpC are the main factors underlying the multifaceted adhesion of S. salivarius and, therefore, play a major role in host colonization.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Aderência Bacteriana
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Glicoproteínas de Membrana
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Adesinas Bacterianas
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Streptococcus salivarius
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Mucosa Intestinal
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Humans
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Male
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article