Chapter 11 Phage strategies 莘大
Chapter 11 Phage strategies
11.1 Introduction 11.2 Lytic development is divided into two periods 11.3 Lytic development is controlled by a cascade 11. 4 Functional clustering in phages T7 and T4 11.5 Lambda immediate early and delayed genes are needed for both lysogeny and the lytic cycle 11. 6 The lytic cycle depends on antitermination 11.7 Lysogeny is maintained by repressor protein 11. 8 Repressor maintains an autogenous circuit 1.9 The repressor and its operators define the immunity region 11.10 The DNA-binding form of repressor is a dimer 11 11 Repressor uses a helix-turn-helix motif to bind dna 11 12 Repressor dimers bind cooperatively to the operator 11.13 Repressor at OR2 interacts with RNa polymerase at PRM 11 14 The cll and clli genes are needed to establish lysogeny 11. 15 PRE is a poor promoter that requires cll protein 11.16 Lysogeny requires several events 11. 1 7 The cro repressor is needed for lytic infection 消当 11.18 What determines the balance between lysogenic and the lytic cycle?
11.1 Introduction 11.2 Lytic development is divided into two periods 11.3 Lytic development is controlled by a cascade 11.4 Functional clustering in phages T7 and T4 11.5 Lambda immediate early and delayed genes are needed for both lysogeny and the lytic cycle 11.6 The lytic cycle depends on antitermination 11.7 Lysogeny is maintained by repressor protein 11.8 Repressor maintains an autogenous circuit 11.9 The repressor and its operators define the immunity region 11.10 The DNA-binding form of repressor is a dimer 11.11 Repressor uses a helix-turn-helix motif to bind DNA 11.12 Repressor dimers bind cooperatively to the operator 11.13 Repressor at OR2 interacts with RNA polymerase at PRM 11.14 The cII and cIII genes are needed to establish lysogeny 11.15 PRE is a poor promoter that requires cII protein 11.16 Lysogeny requires several events 11.17 The cro repressor is needed for lytic infection 11.18 What determines the balance between lysogenic and the lytic cycle?
11.1Introduction Episome is a plasmid able to integrate into bacterial dNA epistasis Immunity in phages refers to the ability of a prophage to prevent another hage of the same type from infecting a cell. It results from the synthesis of phage repressor by the prophage genome Induction refers to the ability of bacteria(or yeast) to synthesize certain enzymes only when their substrates are present; applied to gene expression refers to switching on transcription as a result of interaction of the inducer with the regulator protein Lysogeny describes the ability of a phage to survive in a bacterium as a stable prophage component of the bacterial genome Lytic infection of bacteria by a phage ends in destruction of bacteria and release of progeny phage Plasmid is an autonomous self-replicating extrachromosomal circular DNA Prophage is a phage genome covalently integrated as a linear part of the bacterial chromosome 请莘大
Episome is a plasmid able to integrate into bacterial DNA. Epistasis Immunity in phages refers to the ability of a prophage to prevent another phage of the same type from infecting a cell. It results from the synthesis of phage repressor by the prophage genome. Induction refers to the ability of bacteria (or yeast) to synthesize certain enzymes only when their substrates are present; applied to gene expression, refers to switching on transcription as a result of interaction of the inducer with the regulator protein. Lysogeny describes the ability of a phage to survive in a bacterium as a stable prophage component of the bacterial genome. Lytic infection of bacteria by a phage ends in destruction of bacteria and release of progeny phage. Plasmid is an autonomous self-replicating extrachromosomal circular DNA. Prophage is a phage genome covalently integrated as a linear part of the bacterial chromosome. 11.1 Introduction
11.1 Introduction i Phage DNA Figure ll I Lytic Bacterial DN ■■■ development involves LYTIC C YCLE LYSOGENY the reproduction of phage particles with destruction of the host Phage DNA is rated into bacterial genome bacteria live happily ever after bacterium, but lysogenic ■■■■■ existence allows the from I phage genome to be carried as part of the ogenic bacterium is im mune to further in fection bacterial genetic INDUCTION information 请莘大
Figure 11.1 Lytic development involves the reproduction of phage particles with destruction of the host bacterium, but lysogenic existence allows the phage genome to be carried as part of the bacterial genetic information. 11.1 Introduction
11.1 Introduction Type of Unit Genome Structure Mode of propagation Consequences Lytic phage dsor ss-DN A or RNA Infects susceptible host Usually kills host linear or circular Lysogenic phage ds-DNA Linear sequence in Im munity to infection host chromosome Plasmid ds-DNA cirde Replicates at defined Im munity to plasmids May be transmissible In same group Episome ds-DNA circle Free circle or linear integrated Ma ay transfer host dna Figure 11.2 Several types of independent genetic units exist in bacteria 消当
Figure 11.2 Several types of independent genetic units exist in bacteria. 11.1 Introduction