title: Evolved distal tail carbohydrate binding modules of Lactobacillus phage J-1: a novel type of anti-receptor widespread among lactic acid bacteria phages.
abstract: Bacteriophage replication requires specific host-recognition. Some siphophages harbour a large complex, the baseplate, at the tip of their non-contractile tail. This baseplate holds receptor binding proteins (RBPs) that can recognize the host cell-wall polysaccharide (CWPS) and specifically attach the phage to its host. While most phages possess a dedicated RBP, the phage J-1 that infects Lactobacillus casei seemed to lack one. It has been shown that the phage J-1 distal tail protein (Dit) plays a role in host recognition and that its sequence comprises two inserted modules compared with 'classical' Dits. The first insertion is similar to carbohydrate-binding modules (CBMs), whereas the second insertion remains undocumented. Here, we determined the structure of the second insertion and found it also similar to several CBMs. Expressed insertion CBM2, but not CBM1, binds to L. casei cells and neutralize phage attachment to the bacterial cell wall and the isolated and purified CWPS of L. casei BL23 prevents CBM2 attachment to the host. Electron microscopy single particle reconstruction of the J-1 virion baseplate revealed that CBM2 is projected at the periphery of Dit to optimally bind the CWPS receptor. Taken together, these results identify J-1 evolved Dit as the phage RBP.
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina.|Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Case 932, Marseille Cedex 09, 13288, France.|Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université (AMU), Campus de Luminy, Case 932, Marseille Cedex 09, 13288, France.
authors.forename: Maria-Eugenia
authors.initials: ME
authors.lastname: Dieterle
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Case 932, Marseille Cedex 09, 13288, France.|Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université (AMU), Campus de Luminy, Case 932, Marseille Cedex 09, 13288, France.
authors.forename: Silvia
authors.initials: S
authors.lastname: Spinelli
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France, Université du Littoral-Côte d'Opale, LR2B/UMT 08, Bassin Napoléon, Boulogne-sur-Mer Cedex, BP 120, F-62327, France.
authors.forename: Irina
authors.initials: I
authors.lastname: Sadovskaya
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina.
authors.forename: Mariana
authors.initials: M
authors.lastname: Piuri
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Case 932, Marseille Cedex 09, 13288, France.|Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université (AMU), Campus de Luminy, Case 932, Marseille Cedex 09, 13288, France.
authors.forename: Christian
authors.identifier: 0000-0001-5502-4729
authors.initials: C
authors.lastname: Cambillau
mesh_terms: D001435:Bacteriophages / Q000378:metabolism; D002241:Carbohydrates; D058507:Host Specificity; D019344:Lactic Acid; D007778:Lactobacillus; D007780:Lacticaseibacillus casei / Q000378:metabolism; D013294:Lactococcus lactis / Q000378:metabolism; D008854:Microscopy, Electron; D011485:Protein Binding; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D017376:Viral Tail Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure*; D014771:Virion
chemical_list: D002241:Carbohydrates; D017376:Viral Tail Proteins; D019344:Lactic Acid