INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
artículos
Título:
Exposing the Secrets of Two Well-Known Lactobacillus casei Phages, J-1 and PL-1, by Genomic and Structural Analysi
Autor/es:
DIERTELE, M; BOWMAN, C; BATTHYANY, C; ESTEBAN LANZAROTTI; A.G. TURJANSKI; HATFULL, G; PIURI, M
Revista:
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
Editorial:
AMER SOC MICROBIOLOGY
Referencias:
Lugar: Washington; Año: 2014 vol. 80
ISSN:
0099-2240
Resumen:
Bacteriophage J-1 was isolated in 1965 from an abnormal fermentation of
Yakult using Lactobacillus casei strain Shirota, and a related phage,
PL-1, was subsequently recovered from a strain resistant to J-1.
Complete genome sequencing shows that J-1 and PL-1 are almost identical,
but PL-1 has a deletion of 1.9 kbp relative to J-1, resulting in the
loss of four predicted gene products involved in immunity regulation.
The structural proteins were identified by mass spectrometry analysis.
Similarly to phage A2, two capsid proteins are generated by a
translational frameshift and undergo proteolytic processing. The
structure of gene product 16 (gp16), a putative tail protein, was
modeled based on the crystal structure of baseplate distal tail proteins
(Dit) that form the baseplate hub in other Siphoviridae. However, two
regions of the C terminus of gp16 could not be modeled using this
template. The first region accounts for the differences between J-1 and
PL-1 gp16 and showed sequence similarity to carbohydrate-binding modules
(CBMs). J-1 and PL-1 GFP-gp16 fusions bind specifically to
Lactobacillus casei/paracasei cells, and the addition of l-rhamnose
inhibits binding. J-1 gp16 exhibited a higher affinity than PL-1 gp16
for cell walls of L. casei ATCC 27139 in phage adsorption inhibition
assays, in agreement with differential adsorption kinetics observed for
both phages in this strain. The data presented here provide insights
into how Lactobacillus phages interact with their hosts at the first
steps of infection.