研究生基因表达的调控
合集下载
相关主题
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
基因表达的调控
新陈代谢
酶的活性调节 酶的合成量的调节
精确 快 粗放 慢
基因表达
遗传信息表现为生物性状的过程
微生物基因表达调控
转录水平的调控 转录后水平的调控
基因表达调控 转录、翻译
转录水平的调控
promoter DNA
（P）
Close Complex
（RPC） Regulator
Open Complex
从识别启动子到形成三元复合物，需要4秒
Comparison of the structures of bacterial and eukaryotic RNA polymerases
Geiduschek & Kassavetis, 2001
大肠杆菌及其相关细菌6种RNA聚合酶
70 <rpoD>
E70 家常基因、碳代谢基因
C Mtl II
B
A P
PEP
EI
P-Hpr
(IIIGlc) AGlc
Pyruvate
P-EI
Hpr
P Glucose-6-P P B
C IIGlc
AGlc (IIIGlc)
- S1
S1 Inducer exclusion
- S2
S2
ATP
+
Adenylate
cyclase
cAMP
Catabolite repression
70-type (70, 38, 32, 28, 24, 18)
54-type (54)
Core RNAP (E)
70-RNAP E70
54-RNAP E54
The structures are different, the regulatory modes also
PTS系统
Mannitol
Mannitol-1-P
Glucose
Transient repression by metabolic precursors.
(A) Plac-lacZ expression was characterized for wild-type NCM3722 cells growing exponentially on glycerol, glucose, or lactose as the sole carbon source (red diamonds, squares and triangles, respectively); 1 mM IPTG was added to deactivate LacI. At time zero, 20 mM oaa was added; a transient repression period of ~30 min is shaded in grey. Strain NQ1053 carrying PlacUV5-lacZ (black squares; right y-axis) was not affected. (B) LacZ expression levels before and during the repression period are quantified and shown as the red and black bars. Also quantified are the expression levels of two PTS deletion strains, NQ721 (Δpts, pink) and NQ506 (Δ5EI Δpts, orange). (C)cAMP concentration in the medium were monitored for wild-type cells grown in glycerol (red diamonds) and the two PTS-deletion strains, NQ721 (Δpts) and NQ506 (Δ5EI Δpts), grown in lactose (pink and orange triangles). 20 mM oaa was added at time zero. (D) Relative cAMP excretion rates which reflect the internal cAMP levels were quantified before and during the repression period; (E) in vitro AC activities in strains with and without PTS, NQ385 (pts+), NQ976 (Δpts) or NQ977 (Δ5EI Δpts), were assayed using permeablized cells in the presence or absence of various metabolites. These strains are also deleted of the cAMP phosphodiesterase which is not primary to catabolite repression; (F) in vitro AC activities in NQ385 were assayed with 0-10 mM of various metabolites. The lines show the bestfit to simple inhibition kinetics y =1/ (1+ x / KI ) , where y is the relative AC activity, x is the metabolite concentration. KI, the half-inhibition concentration, is found to be 0.84±0.04 mM, 0.63±0.02 mM and 1.76±0.05 mM for oaa, pyr, akg respectively. (G) oaa transiently represses PlacZ-lacZ expression in PTS-deleted cells, NQ721 (Δpts) and NQ506 (Δ5EI Δpts), grown exponentially in lactose. 20 mM oaa was supplied at time zero. Relative LacZ activities before and during this transient repression were quantified in (B); (H) Growth rate dependence of the steady state Plac-lacZ expression in PTS mutants under various modes of C-limitations: The circles indicate the results for strains [NQ721 (Δpts, pink) and NQ506 (Δ5EI Δpts, orange)] grown in various carbon sources, and triangles indicate the result of strains [NQ773 (Δpts with titratable LacY; pink) and NQ567 (Δ5EI Δpts with titratable LacY; orange triangles)] grown in lactose with varying degrees of LacY titration. The two dashed lines show the best linear fits to Eq. [1], with λC = 1.16±0.02 h-1 (r2=0.92) in Δpts background (NQ721, NQ773) and λC = 1.19±0.02 h-1 (r2=0.78) in Δ5EI Δpts
（RPO）
Ternary Complex
（RPi）
RNAP
（R）
mRNA
转录起始调控中的一些关键元件 DNA序列：顺式作用元件 RNAP：RNA聚合酶 转录调节蛋白： 反式作用因子 RNAP与DNA、调节蛋白与DNA以及调
节蛋白与RNAP之间相互作用 闭合复合体：Close complex 开放复合体：Open complex 三元复合物
32 <rpoBiblioteka Baidu>
E32 热休克基因
24 <rpoE> 2’ E24 极端热休克基因
28 <rpoF>
E28 鞭毛－趋向性基因
38 <rpoS> (core) E38 氧 化 胁 迫 响 应 基 因 稳定期特异性基因
54 <rpoN>
E54 氮代谢基因
Transcription in Bacteria:
新陈代谢
酶的活性调节 酶的合成量的调节
精确 快 粗放 慢
基因表达
遗传信息表现为生物性状的过程
微生物基因表达调控
转录水平的调控 转录后水平的调控
基因表达调控 转录、翻译
转录水平的调控
promoter DNA
（P）
Close Complex
（RPC） Regulator
Open Complex
从识别启动子到形成三元复合物，需要4秒
Comparison of the structures of bacterial and eukaryotic RNA polymerases
Geiduschek & Kassavetis, 2001
大肠杆菌及其相关细菌6种RNA聚合酶
70 <rpoD>
E70 家常基因、碳代谢基因
C Mtl II
B
A P
PEP
EI
P-Hpr
(IIIGlc) AGlc
Pyruvate
P-EI
Hpr
P Glucose-6-P P B
C IIGlc
AGlc (IIIGlc)
- S1
S1 Inducer exclusion
- S2
S2
ATP
+
Adenylate
cyclase
cAMP
Catabolite repression
70-type (70, 38, 32, 28, 24, 18)
54-type (54)
Core RNAP (E)
70-RNAP E70
54-RNAP E54
The structures are different, the regulatory modes also
PTS系统
Mannitol
Mannitol-1-P
Glucose
Transient repression by metabolic precursors.
(A) Plac-lacZ expression was characterized for wild-type NCM3722 cells growing exponentially on glycerol, glucose, or lactose as the sole carbon source (red diamonds, squares and triangles, respectively); 1 mM IPTG was added to deactivate LacI. At time zero, 20 mM oaa was added; a transient repression period of ~30 min is shaded in grey. Strain NQ1053 carrying PlacUV5-lacZ (black squares; right y-axis) was not affected. (B) LacZ expression levels before and during the repression period are quantified and shown as the red and black bars. Also quantified are the expression levels of two PTS deletion strains, NQ721 (Δpts, pink) and NQ506 (Δ5EI Δpts, orange). (C)cAMP concentration in the medium were monitored for wild-type cells grown in glycerol (red diamonds) and the two PTS-deletion strains, NQ721 (Δpts) and NQ506 (Δ5EI Δpts), grown in lactose (pink and orange triangles). 20 mM oaa was added at time zero. (D) Relative cAMP excretion rates which reflect the internal cAMP levels were quantified before and during the repression period; (E) in vitro AC activities in strains with and without PTS, NQ385 (pts+), NQ976 (Δpts) or NQ977 (Δ5EI Δpts), were assayed using permeablized cells in the presence or absence of various metabolites. These strains are also deleted of the cAMP phosphodiesterase which is not primary to catabolite repression; (F) in vitro AC activities in NQ385 were assayed with 0-10 mM of various metabolites. The lines show the bestfit to simple inhibition kinetics y =1/ (1+ x / KI ) , where y is the relative AC activity, x is the metabolite concentration. KI, the half-inhibition concentration, is found to be 0.84±0.04 mM, 0.63±0.02 mM and 1.76±0.05 mM for oaa, pyr, akg respectively. (G) oaa transiently represses PlacZ-lacZ expression in PTS-deleted cells, NQ721 (Δpts) and NQ506 (Δ5EI Δpts), grown exponentially in lactose. 20 mM oaa was supplied at time zero. Relative LacZ activities before and during this transient repression were quantified in (B); (H) Growth rate dependence of the steady state Plac-lacZ expression in PTS mutants under various modes of C-limitations: The circles indicate the results for strains [NQ721 (Δpts, pink) and NQ506 (Δ5EI Δpts, orange)] grown in various carbon sources, and triangles indicate the result of strains [NQ773 (Δpts with titratable LacY; pink) and NQ567 (Δ5EI Δpts with titratable LacY; orange triangles)] grown in lactose with varying degrees of LacY titration. The two dashed lines show the best linear fits to Eq. [1], with λC = 1.16±0.02 h-1 (r2=0.92) in Δpts background (NQ721, NQ773) and λC = 1.19±0.02 h-1 (r2=0.78) in Δ5EI Δpts
（RPO）
Ternary Complex
（RPi）
RNAP
（R）
mRNA
转录起始调控中的一些关键元件 DNA序列：顺式作用元件 RNAP：RNA聚合酶 转录调节蛋白： 反式作用因子 RNAP与DNA、调节蛋白与DNA以及调
节蛋白与RNAP之间相互作用 闭合复合体：Close complex 开放复合体：Open complex 三元复合物
32 <rpoBiblioteka Baidu>
E32 热休克基因
24 <rpoE> 2’ E24 极端热休克基因
28 <rpoF>
E28 鞭毛－趋向性基因
38 <rpoS> (core) E38 氧 化 胁 迫 响 应 基 因 稳定期特异性基因
54 <rpoN>
E54 氮代谢基因
Transcription in Bacteria: