Format

Send to

Choose Destination

See 1 citation found by title matching your search:

Viruses. 2017 Nov 17;9(11). pii: E343. doi: 10.3390/v9110343.

The Ms6 Mycolyl-Arabinogalactan Esterase LysB is Essential for an Efficient Mycobacteriophage-Induced Lysis.

Author information

1
Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal. amsgigante@ff.ulisboa.pt.
2
Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30345, USA. cheri.m.hampton@emory.edu.
3
Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30345, USA. rebecca.s.dillard@emory.edu.
4
Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal. filipagil@hotmail.com.
5
Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal. mjcatalao@ff.ulisboa.pt.
6
Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal. jpereira@ff.ulisboa.pt.
7
Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, 30345, USA. erwrigh@emory.edu.
8
Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, 1649-003, Portugal. mpimentel@ff.ulisboa.pt.

Abstract

All dsDNA phages encode two proteins involved in host lysis, an endolysin and a holin that target the peptidoglycan and cytoplasmic membrane, respectively. Bacteriophages that infect Gram-negative bacteria encode additional proteins, the spanins, involved in disruption of the outer membrane. Recently, a gene located in the lytic cassette was identified in the genomes of mycobacteriophages, which encodes a protein (LysB) with mycolyl-arabinogalactan esterase activity. Taking in consideration the complex mycobacterial cell envelope that mycobacteriophages encounter during their life cycle, it is valuable to evaluate the role of these proteins in lysis. In the present work, we constructed an Ms6 mutant defective on lysB and showed that Ms6 LysB has an important role in lysis. In the absence of LysB, lysis still occurs but the newly synthesized phage particles are deficiently released to the environment. Using cryo-electron microscopy and tomography to register the changes in the lysis phenotype, we show that at 150 min post-adsorption, mycobacteria cells are incompletely lysed and phage particles are retained inside the cell, while cells infected with Ms6wt are completely lysed. Our results confirm that Ms6 LysB is necessary for an efficient lysis of Mycobacterium smegmatis, acting, similarly to spanins, in the third step of the lysis process.

KEYWORDS:

LysB; Ms6; bacteriophage lysis; cryo-electron microscopy; mycobacteria; mycobacteriophage; spanins

PMID:
29149017
PMCID:
PMC5707550
DOI:
10.3390/v9110343
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Multidisciplinary Digital Publishing Institute (MDPI) Icon for PubMed Central
Loading ...
Support Center