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North Terrace Campus
Level 4, Molecular Life Sciences
The University of Adelaide
SA 5005
AUSTRALIA
Renato Morona

Telephone: +61 8 8303 4151
Facsimile: +61 8 8303 7532

Bacteriophage Sf6 and TSP

  

  

Sf6 is a temperate bacteriophage of Shigella flexneri and infects Y (and X) serotype strains. The receptor for Sf6 is the lipopolysaccharide (LPS) O antigen. The sequence of the Sf6 genome has been determined.  Sf6 lysogeny results in serotype conversion (Y to 3b).  The Sf6 oac gene encodes an acetyl transferase that modifies the Y serotype O antigen.

Adsoption to the O antigen is mediated by the tail spike proteins (TSPs). TSP also has endorhamnosidase activity and is able to hydrolyse the LPS O antigen chains from >100 repeat units down to 4-6 repeat units. TSP is useful in studying O antigen and the cell surface molecules of S. flexneri.

Relevant publications

Chua, J. E.H., Manning, P.A., and Morona, R. (1999) “The Shigella flexneri bacteriophage Sf6 tailspike protein (TSP)/endorhamnosidase is related to the bacteriophage P22 TSP and has a motif common to exo- and endoglycanases, and C-5 epimerases.” Microbiol. 145: 1649-1659.

Freiberg, A., Morona, R., Van Den Bosch, L., Jung, C., Behlke, J., Carlin, N, Seckler, R., and Baxa, U. (2003) “The tailspike protein of Shigella phage Sf6: A structural homolog of Salmonella phage P22 tailspike without sequence similarity in the b-helix domain.” J. Biol. Chem. 278: 1542-1548

Casjeans, S., Winn-Stapley, D.A., Gilcrease, E., Morona, R., Kühlewein, C., Chua, J.E.H., Manning., P.A., Inwood., W., and Clark., A.J. (2004) "The chromosome of Shigella flexneri bacteriophage Sf6: complete nucleotide sequence, genetic mosaicism, and DNA packaging."  J. Mol. Biol. 339: 379-394.

Morona, R., and Van Den Bosch, L. (2003) "Lipopolysaccharide O antigen chains mask IcsA(VirG) in Shigella flexneri" FEMS Microbiol. Lett. 221: 173-180.

Bacteriophage SfII

SfII is a temperate bacteriophage of S. flexneri, and lysogeny with SfII results in serotype conversion. SfII encoded gtrII gene activity results in Y serotype LPS O antigen being modified by glucosylation, and the O antigen produced by lysogens has the 2a serotype. 

Relevant publications

Mavris, M., Manning, P.A., and Morona, R. (1997) “Mechanism of bacteriophage SfII mediated serotype conversion in Shigella flexneri”. Mol. Microbiol. 26: 939-950.

Korres, H., Mavris, M., Morona, R., Manning, P.A., and Verma, N. (2005) "Topological analysis of GtrA and GtrB proteins encoded by the serotype-converting cassette of Shigella flexneri." Biochem. Biophys. Res. Comm. 328: 1252-1260.