Identification of Dual Receptor Binding Protein Systems in Lactococcal 936 Group Phages

Stephen Hayes (1) , Yoan Duhoo (2) , Horst H. Neve (3) , James Murphy (4) , Jean-Paul Noben (5) , Charles M. A. P. Franz (6) , Christian Cambillau (2) , Jennifer Mahony (7) , Arjen Nauta (8) , Douwe van Sinderen (9)

1 UCC - University College Cork
2 AFMB - Architecture et fonction des macromolécules biologiques
3 Dept Microbiol & Biotechnol
4 University of Melbourne
5 UHasselt - Hasselt University
6 Department of Safety and Quality of Fruit and Vegetables
7 School of Microbiology
8 FrieslandCampina
9 Alimentary Pharmabiot Ctr, Biosci Inst, Dept Microbiol

Siphoviridae of the lactococcal 936 group are the most commonly encountered bacteriophages in the dairy processing environment. The 936 group phages possess a discrete baseplate at the tip of their tail-a complex harbouring the Receptor Binding Protein (RBP) which is responsible for host recognition and attachment. The baseplate-encoding region is highly conserved amongst 936 phages, with 112 of 115 publicly available phages exhibiting complete synteny. Here, we detail the three exceptions (Phi4.2, Phi4R15L, and Phi4R16L), which differ from this genomic architecture in possessing an apparent second RBP-encoding gene upstream of the "classical" rbp gene. The newly identified RBP possesses an elongated neck region relative to currently defined 936 phage RBPs and is genetically distinct from defined 936 group RBPs. Through detailed characterisation of the representative phage Phi4.2 using a wide range of complementary techniques, we demonstrated that the above-mentioned three phages possess a complex and atypical baseplate structure. Furthermore, the presence of both RBPs in the tail tip of the mature virion was confirmed, while the anticipated host-binding capabilities of both proteins were also verified.

Mots clés: virus; structure; host interactions; lactic acid bacteria

Domaines: Biochimie [q-bio.BM]

Stephen Hayes, Yoan Duhoo, Horst H. Neve, James Murphy, Jean-Paul Noben, et al.. Identification of Dual Receptor Binding Protein Systems in Lactococcal 936 Group Phages. Viruses, 2018, 10 (12), pp.668. ⟨10.3390/v10120668⟩. ⟨hal-02094461⟩