Exposing the secrets of two well known Lactobacillus casei phages: Genomic and structural analysis of J-1 and PL-1

MARIA EUGENIA DIETERLE; CHARLES BOWMAN; CARLOS BATTHYANY; ESTEBAN LANZAROTTI; TURJANSKI A; GRAHAM F HATFULL; MARIANA PIURI

Rosario

Congreso; L Reunión Anual SAIB; 2014

SAIB

<!-- /* Font Definitions */ @font-face {font-family:Arial; panose-1:2 11 6 4 2 2 2 2 2 4; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:-536859905 -1073711037 9 0 511 0;} @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:-520092929 1073786111 9 0 415 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-ansi-language:ES-AR;} p {mso-style-priority:99; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:11.0pt; mso-ansi-font-size:11.0pt; mso-bidi-font-size:11.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-ansi-language:ES-AR;} .MsoPapDefault {mso-style-type:export-only; margin-bottom:10.0pt; line-height:115%;} @page WordSection1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.WordSection1 {page:WordSection1;} --> Bacteriophages infecting lactic acid bacteria constitute a threat for dairy fermentations. Knowledge of phage-host interactions is a valuable tool for the design of rational strategies against infection. We have sequenced and annotated the genomes of phages J-1 (isolated from an abnormal fermentation of Yakult) and PL-1 (isolated from a J-1 derived resistant strain). Both genomes are almost identical but PL-1 has a deletion of 1.9 kbp in the immunity region and also differs in gene 16 (tail component). All the structural proteins were identified by mass spectrometry analysis. The structure of gp16 was modeled based on distal tail proteins. However, a region that accounts for the differences between J-1 and PL-1 gp16 could not be fitted in the model and showed sequence similarity to carbohydrate-binding modules. J-1 and PL-1 gfp-gp16 fusions specifically bind to Lactobacillus casei/paracasei cells and addition of L-rhamnose inhibits binding of the recombinant protein and entire phage particles as well. Phage adsorption inhibition assays revealed a higher affinity of J-1 gp16 for cell walls of L. casei ATCC 27139 in agreement with differential adsorption kinetics observed for both phages in this strain. Altogether, this is the first report of an isolated Dit-like protein interacting with the cell surface and probably involved in determination of the host range.