RecFinder – a new tool to find phage proteins responsible for host recognition

(Bacterio)phages are bacterial viruses that represent the most abundant and genetically diverse biological entities on the planet [1,2]. The largest virus group, the order Caudovirales (containing 96% of all known phages), has evolved recognition peptides for efficient virus-host interaction [3]. The peptides, usually located at the phage tail fiber, baseplate and other tail proteins mediate recognition and attachment specifically to bacterial cell wall receptors - lipopolysaccharides, teichoic acids, proteins and flagella. These proteins responsible for host recognition and binding (HBP) are macromolecular machines that make the process of infection highly efficient and finely regulated, and most likely play an important role in the evolutionary success of tailed phages. As a result of this specific binding affinity certain phages can only infect certain bacteria, determining in this manner the phage host range [4]. (...

Host-Endolysins interactions

37 Host-Endolysins interactions Franklin L. Nobrega, Silvio Santos, Eugénio C. Ferreira, Joana Azeredo, Leon D. Kluskens IBB – Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal Abstract (Bacterio)phages are viruses that specifically infect bacteria. They are tremendously diverse and the most abundant living entities on Earth with an estimated total population size of 1031 phage particles. During infection they inject their DNA in the host bacteria and drive the cell machinery to produce new progeny phages. At the end of the infection cycle, phages (with the exception of a few known filamentous phages) produce enzymes called (endo)lysins that degrade the peptidoglycan (PG) leading to bacterial lysis and death in order to release the progeny virions. PG is a heteropolymer that protects the bacterial cell against osmotic pressure. The ability of endolysins to degrade PG causing the death of the bacterial cell makes these enzymes a very interesting biocontrol agent against problematic antibiotic resistant pathogenic bacteria. (..