Chapter 4 bacteriophage
Chapter 4 bacteriophage
Bacteriophages( phages )are obligate intracellular parasites that multiply inside bacteria by making use of some or all of the host biosynthetic machinery. They are viruses that infect bacteria
◼ Bacteriophages ( phages ) are obligate intracellular parasites that multiply inside bacteria by making use of some or all of the host biosynthetic machinery . They are viruses that infect bacteria
Composition of Bacteriophage Nucleic acid: either dna or rna but not both ds dNa Ss rNa ss dna unusual or modified bases encode 3-5 gene products to over 100 gene products Protein function in infection and protect the nucleic acid
Composition of Bacteriophage ◼ Nucleic acid: either DNA or RNA but not both ◼ ds DNA, ss RNA, ss DNA ◼ unusual or modified bases ◼ encode 3-5 gene products to over 100 gene products ◼ Protein: function in infection and protect the nucleic acid
Structure of Bacteriophage different sizes and shapes T3 phage icosahedral head 0x60nm.+面体 tail 20nm long T4 phage dsDNA T1 phage head 80x 11Onm dsDN tail 110nm long head 54x54nm tail 140nm long M13 phage filamentous BSDNA helical 80010nm
Structure of Bacteriophage ◼ different sizes and shapes icosahedral 二十面体 filamentous
Capsid DNA Head Contractile Sheath Tail Tail fibers Base plate
Tail Tail Fibers Base Plate Head Contractile Sheath Capsid DNA