Haemophilus influenzae HP1 Bacteriophage Encodes a Lytic Cassette with a Pinholin and a Signal-Arrest-Release Endolysin.
Int J Mol Sci
; 21(11)2020 Jun 04.
Article
en En
| MEDLINE
| ID: mdl-32512736
HP1 is a temperate bacteriophage, belonging to the Myoviridae family and infecting Haemophilus influenzae Rd. By in silico analysis and molecular cloning, we characterized lys and hol gene products, present in the previously proposed lytic module of HP1 phage. The amino acid sequence of the lys gene product revealed the presence of signal-arrest-release (SAR) and muraminidase domains, characteristic for some endolysins. HP1 endolysin was able to induce lysis on its own when cloned and expressed in Escherichia coli, but the new phage release from infected H. influenzae cells was suppressed by inhibition of the secretion (sec) pathway. Protein encoded by hol gene is a transmembrane protein, with unusual C-out and N-in topology, when overexpressed/activated. Its overexpression in E. coli did not allow the formation of large pores (lack of leakage of ß-galactosidase), but caused cell death (decrease in viable cell count) without lysis (turbidity remained constant). These data suggest that lys gene encodes a SAR-endolysin and that the hol gene product is a pinholin. HP1 SAR-endolysin is responsible for cell lysis and HP1 pinholin seems to regulate the cell lysis and the phage progeny release from H. influenzae cells, as new phage release from the natural host was inhibited by deletion of the hol gene.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Endopeptidasas
/
Bacteriófagos
/
Proteínas Virales
/
Regulación Viral de la Expresión Génica
/
Haemophilus influenzae
Idioma:
En
Revista:
Int J Mol Sci
Año:
2020
Tipo del documento:
Article
País de afiliación:
Polonia