The Acetylglucosaminidase LytB of Streptococcus pneumoniae is Involved in the Structure and Formation of Biofilms

The N-acetylglucosaminidase LytB of Streptococcus pneumoniae is involved in nasopharyngeal colonization and is responsible for cell separation at the end of cell division; thus, ΔlytB mutants form long chains of cells. This paper reports the construction and properties of a defective pneumococcal mu...

Descripción completa

Detalles Bibliográficos
Autores: Domenech Lucas, Miriam, García, Ernesto
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:dnet:docta_______::c4fa7c272d863c7924926bab5cc378da
Acceso en línea:https://hdl.handle.net/20.500.14352/98133
Access Level:acceso abierto
Palabra clave:579.25
Pneumococcus
Biofilm
LytB glucosaminidase
Choline-binding protein
Genética
Microbiología (Biología)
2409 Genética
2414 Microbiología
Descripción
Sumario:The N-acetylglucosaminidase LytB of Streptococcus pneumoniae is involved in nasopharyngeal colonization and is responsible for cell separation at the end of cell division; thus, ΔlytB mutants form long chains of cells. This paper reports the construction and properties of a defective pneumococcal mutant producing an inactive LytB protein (LytBE585A). It is shown that an enzymatically active LytB is required for in vitro biofilm formation, as lytB mutants (either ΔlytB or producing the inactive LytBE585A) are incapable of forming substantial biofilms, despite that extracellular DNA is present in the biofilm matrix. Adding small amounts (0.5 to 2.0 μg/ml) of exogenous LytB or some LytB constructs restored the biofilm-forming capacity of lytB mutants to wild-type levels. The LytBE585A mutant formed biofilm more rapidly than ΔlytB mutants in the presence of LytB. This suggests that the mutant protein acted in a structural role, likely through the formation of complexes with extracellular DNA. The chain-dispersing capacity of LytB allowed the separation of daughter cells, presumably facilitating the formation of microcolonies and, finally, of biofilms. A role for the possible involvement of LytB in the synthesis of the extracellular polysaccharide component of the biofilm matrix is also discussed.