分子生物学课件λ噬菌体基因表达的调控
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λ噬菌体基因表达的调控
2006
烈性噬菌体（lytic phages） 温和噬菌体（temperate phages）
Lytic versus lysogenic infection by phage 入
Genetic map of phage 入
λphage developing stage
anti-sense CRO-mRNA
Establishes & Maintenance Lysogenic
RNApol PLOL N-p & CIII-p Positive Pint
Int-p
CII-p
CI-P is bound to OR (and OL) and cl is being actively transcribed from the PRM promoter.
Late stage
UV or 木 瓜蛋白酶
CI
Rec.A
PR OR3 OR2 OR1 CRO
CI
PRM
PR OR3 OR2 OR1 CRO
PRM
The battle between cl and cro.
Late stage CI-p monomer U.V or 木瓜蛋白酶… cleavage
The RecA coprotease unmasks a protease activity in the repressor, so it can cleave itself.
The severed repressor falls off the operator, allowing polymerase to bindΒιβλιοθήκη Baiduto PR and transcribe cro. Lysogeny is broken.
PLOL
CI
PROR
PRM
CI-P
CI-P
CI mRNA + anti RNA of CRO
Establishes Maintenance
Lysogenic
PLOL
CI mRNA + anti RNA of CRO
CI PLOL
PR CRO
PR CRO
PRM
PRE
CI
PRM
PRE
Maintaining lysogeny
RNApol
PLOL
Stop at TR 1
transcription N-p
Stop at TL 1
Early stage
CRO-p
Early
Head Tail
cos
PROR CRO tR1 CII O P Q S R
cos
tL2 int Pint Xis CIII tL1 N OL PL CI PRM
For CI-p (repressor) For CRO-p (repressor)
OR1 ＞ OR2 ＝ OR3 OR1 ＝ OR2 ＜ OR3
N-p Anti-termination protein
for delayed early stage Q-p Anti-termination protein
Operator (cis-factor)
OR (OR1, OR2, OR3), OL (OL1, OL2, OL3)
OR3
CI
OR2
PR
CRO
OR1
PRM
G/C as axis IR seq of 17 bp
OL3
OL2
OL1
CI
OR1, OR2, OR3 序列的差异， 决定了CI-p, CRO-p与其的结合力
Delayed early stage
CRO-p CII-p
Head Tail
cos
PROR CRO tR1 CII O P Q S R
tL2 int Pint Xis CIII tL1 N OL PL CI PRM
P RE
CIII-p
CI + anti-sense CRO-mRNA
Delayed early stage
P RE
Early
N-P Anti-termination
Delayed early stage
Anti-termination in Rho-dependent terminator
TR1; Rho-dependent terminator 8s Cro RNA
Np
NuTR
Cro
CII
16s RNA
The purpose of λphage infection E.coli Lysis the host of E.coli
自然选择形成； ---λphage host RNApol. binding PROR
early stage
CRO-p
---CRO-p binding OR3
off PRM
具有选择 lytic 趋势
Promoter
PRM (Promoter for Repressor-Maintenance) PM (Promoter for lysogenic -Maintenance) Located between OR2—OR3 Weak promoter (1/7 ~ 1/8 of PRE) Positive control site with CI-p Negative control site with CI-p & CRO-p Transcription CI gene
• Establishing lysogeny. Delayed early transcription from PR gives cll mRNA that is translated to CII . • CII allows RNA polymerase to bind to PRE and transcribe the cl gene, yielding repressor .
λphage发育途径选择调控区的基因组成
late Delayed early Early
late Delayed early Early
Head Tail
cos
PROR CRO tR1 CII O P Q S R
cos
tL2 int Pint Xis CIII tL1 N OL PL CI PRM
动态平衡破坏 PR on
PRM off
OR3 + CRO-p
转录 RNApol. 转 录
Late stage Head &tail genes positive Q-p Q, P, R, S…..
Lytic stage
Late stage
---other controlling system for Lytic way selection •CII-p competition with CRO-p
• HFL gene control
HFL gene
(high frequency lysogenesis) mut. hfl
HFL-p When [C] starved
degradation CII-p
lytic
HFL gene off (筹集粮草)
CII-p
Positive.
Lysogenic
Pint (Promoter for Integration) Located on the downstream of CIII Positive control with CII-p & CIII-p
Early stage;
Regulation model
RNApol
PROR transcription CRO-p
P RE
Cis- factor
Trans-factor
For replication
λphage发育途径选择调控区的基因组成
C gene （与溶原直接相关）
λ host lysogenic tuibid colony C gene mut. lytic Clear plaque
CI cI 可建立溶原，但不易维持，溶原率 <10-5 CI-p 26kd as repressor binding on PR---OR, PL---OL （负控制） as expressor for CI self （ 正控制）
CII cII 不易建立溶原，一旦建立溶原后， 依靠CI-p可保持溶原率10-4—10-5
CII-p as expressor 启动PRE 转录CI gene
CIII cIII 参与溶原建立过程，但对溶原化作 用不大溶原率10-1—10-2
CIII-p as expressor 启动PRE 转录 CI gene
Promoter
PR (Promoter on Right) Located between OR1 — OR2 Negative control site with CI-p & CRO-p Transcription CRO, CII, O, P, Q, S, R, H, T genes
PL (Promoter on left) Located between OL1 — OL2 Negative control site with CI-p & CII-p Transcription N, CIII genes
for late stage
Promoter
PRE ( Promoter for Repressor-Establishment ) PE ( Promoter for lysogenic-Establishment ) Located between CRO---CII Strong promoter Positive control site with CII-p,CIII-p Transcription CI gene & anti-sense CRO RNA
Immediate early stage; N & Cro genes transcription from PL & PR
Delayed early stage; N-p required for anti-termination at TL & TR
Late stage; Q-p required
Delayed early stage
RNApol
PROR PLOL
transcription CRO-p & CII-p transcription N-p & CIII-p
PR off
OR1,OR2 repression CI-p
PRE Positive
Positive
CI-p
PRM
transcription
2006
烈性噬菌体（lytic phages） 温和噬菌体（temperate phages）
Lytic versus lysogenic infection by phage 入
Genetic map of phage 入
λphage developing stage
anti-sense CRO-mRNA
Establishes & Maintenance Lysogenic
RNApol PLOL N-p & CIII-p Positive Pint
Int-p
CII-p
CI-P is bound to OR (and OL) and cl is being actively transcribed from the PRM promoter.
Late stage
UV or 木 瓜蛋白酶
CI
Rec.A
PR OR3 OR2 OR1 CRO
CI
PRM
PR OR3 OR2 OR1 CRO
PRM
The battle between cl and cro.
Late stage CI-p monomer U.V or 木瓜蛋白酶… cleavage
The RecA coprotease unmasks a protease activity in the repressor, so it can cleave itself.
The severed repressor falls off the operator, allowing polymerase to bindΒιβλιοθήκη Baiduto PR and transcribe cro. Lysogeny is broken.
PLOL
CI
PROR
PRM
CI-P
CI-P
CI mRNA + anti RNA of CRO
Establishes Maintenance
Lysogenic
PLOL
CI mRNA + anti RNA of CRO
CI PLOL
PR CRO
PR CRO
PRM
PRE
CI
PRM
PRE
Maintaining lysogeny
RNApol
PLOL
Stop at TR 1
transcription N-p
Stop at TL 1
Early stage
CRO-p
Early
Head Tail
cos
PROR CRO tR1 CII O P Q S R
cos
tL2 int Pint Xis CIII tL1 N OL PL CI PRM
For CI-p (repressor) For CRO-p (repressor)
OR1 ＞ OR2 ＝ OR3 OR1 ＝ OR2 ＜ OR3
N-p Anti-termination protein
for delayed early stage Q-p Anti-termination protein
Operator (cis-factor)
OR (OR1, OR2, OR3), OL (OL1, OL2, OL3)
OR3
CI
OR2
PR
CRO
OR1
PRM
G/C as axis IR seq of 17 bp
OL3
OL2
OL1
CI
OR1, OR2, OR3 序列的差异， 决定了CI-p, CRO-p与其的结合力
Delayed early stage
CRO-p CII-p
Head Tail
cos
PROR CRO tR1 CII O P Q S R
tL2 int Pint Xis CIII tL1 N OL PL CI PRM
P RE
CIII-p
CI + anti-sense CRO-mRNA
Delayed early stage
P RE
Early
N-P Anti-termination
Delayed early stage
Anti-termination in Rho-dependent terminator
TR1; Rho-dependent terminator 8s Cro RNA
Np
NuTR
Cro
CII
16s RNA
The purpose of λphage infection E.coli Lysis the host of E.coli
自然选择形成； ---λphage host RNApol. binding PROR
early stage
CRO-p
---CRO-p binding OR3
off PRM
具有选择 lytic 趋势
Promoter
PRM (Promoter for Repressor-Maintenance) PM (Promoter for lysogenic -Maintenance) Located between OR2—OR3 Weak promoter (1/7 ~ 1/8 of PRE) Positive control site with CI-p Negative control site with CI-p & CRO-p Transcription CI gene
• Establishing lysogeny. Delayed early transcription from PR gives cll mRNA that is translated to CII . • CII allows RNA polymerase to bind to PRE and transcribe the cl gene, yielding repressor .
λphage发育途径选择调控区的基因组成
late Delayed early Early
late Delayed early Early
Head Tail
cos
PROR CRO tR1 CII O P Q S R
cos
tL2 int Pint Xis CIII tL1 N OL PL CI PRM
动态平衡破坏 PR on
PRM off
OR3 + CRO-p
转录 RNApol. 转 录
Late stage Head &tail genes positive Q-p Q, P, R, S…..
Lytic stage
Late stage
---other controlling system for Lytic way selection •CII-p competition with CRO-p
• HFL gene control
HFL gene
(high frequency lysogenesis) mut. hfl
HFL-p When [C] starved
degradation CII-p
lytic
HFL gene off (筹集粮草)
CII-p
Positive.
Lysogenic
Pint (Promoter for Integration) Located on the downstream of CIII Positive control with CII-p & CIII-p
Early stage;
Regulation model
RNApol
PROR transcription CRO-p
P RE
Cis- factor
Trans-factor
For replication
λphage发育途径选择调控区的基因组成
C gene （与溶原直接相关）
λ host lysogenic tuibid colony C gene mut. lytic Clear plaque
CI cI 可建立溶原，但不易维持，溶原率 <10-5 CI-p 26kd as repressor binding on PR---OR, PL---OL （负控制） as expressor for CI self （ 正控制）
CII cII 不易建立溶原，一旦建立溶原后， 依靠CI-p可保持溶原率10-4—10-5
CII-p as expressor 启动PRE 转录CI gene
CIII cIII 参与溶原建立过程，但对溶原化作 用不大溶原率10-1—10-2
CIII-p as expressor 启动PRE 转录 CI gene
Promoter
PR (Promoter on Right) Located between OR1 — OR2 Negative control site with CI-p & CRO-p Transcription CRO, CII, O, P, Q, S, R, H, T genes
PL (Promoter on left) Located between OL1 — OL2 Negative control site with CI-p & CII-p Transcription N, CIII genes
for late stage
Promoter
PRE ( Promoter for Repressor-Establishment ) PE ( Promoter for lysogenic-Establishment ) Located between CRO---CII Strong promoter Positive control site with CII-p,CIII-p Transcription CI gene & anti-sense CRO RNA
Immediate early stage; N & Cro genes transcription from PL & PR
Delayed early stage; N-p required for anti-termination at TL & TR
Late stage; Q-p required
Delayed early stage
RNApol
PROR PLOL
transcription CRO-p & CII-p transcription N-p & CIII-p
PR off
OR1,OR2 repression CI-p
PRE Positive
Positive
CI-p
PRM
transcription