The mycobacteriophage Ms6 encodes a chaperone-like protein involved in the endolysin delivery to the peptidoglycan
Article first published online: 1 JUN 2010
© 2010 Blackwell Publishing Ltd
Volume 77, Issue 3, pages 672–686, August 2010
How to Cite
Catalão, M. J., Gil, F., Moniz-Pereira, J. and Pimentel, M. (2010), The mycobacteriophage Ms6 encodes a chaperone-like protein involved in the endolysin delivery to the peptidoglycan. Molecular Microbiology, 77: 672–686. doi: 10.1111/j.1365-2958.2010.07239.x
- Issue published online: 18 JUL 2010
- Article first published online: 1 JUN 2010
- Accepted 21 May, 2010.
Like most double-stranded (ds) DNA phages, mycobacteriophage Ms6 uses the holin-endolysin system to achieve lysis of its host. In addition to endolysin (lysA) and holin (hol) genes, Ms6 encodes three accessory lysis proteins. In this study we investigated the lysis function of Gp1, which is encoded by the gp1 gene that lies immediately upstream of lysA. Escherichia coli lysis was observed after coexpression of LysA and Gp1 in the absence of Ms6 holin. Gp1 does not belong to the holin class of proteins, and we provide evidence that it shares several characteristics with molecular chaperones. We show that Gp1 interacts with LysA, and that this interaction is necessary for LysA delivery to its target. In addition, PhoA fusions showed that, in Mycobacterium smegmatis, LysA is exported to the extracytoplasmic environment in the presence of Gp1. We also show that Gp1 is necessary for efficient M. smegmatis lysis, as Ms6 gp1 deletion results in host lysis defects. We propose that delivery of Ms6 endolysin to the murein layer is assisted by Gp1, a chaperone-like protein, in a holin-independent manner.