第八章 克隆基因的表达Expression of Cloned Genes

Gene Organization

Gene Expression and Regulation Levels

The lac Operon

Structure and expression of the mammalian β-globin gene

Transcription and Translation

Transcription in Prokaryotes

Structure of a typical promoter in E.coli

S-D Recognition Sequences in Prokaryotic mRNAs

Termination of RNA Chains

Expression Vector

Secretion Cloning Vector

Fusional ExpressionVector

Factor Xa---Activated form of factor x that participates in both the intrinsic and extrinsic pathways of blood coagulation. It catalyses the conversion of prothrombin to thrombin in conjunction with other cofactors.

Conserved Sequences in Promoters

Distance of Structure Genes and Promoters

Gene expression

level and secondary

structure of mRNA

Alteration of the Distance between Gene and Promoter

Translation Reading Frame

Construction the Reading Frame

Induced Expression of Gene

• Chemical---lac promoter and IPTG

IPTG 即 Isopropyl β-D-1-thiogalactopyranoside ，也称 Isopropyl β-D-thiogalactoside ，中文名为异丙基 -β-D- 硫代半乳糖苷。分子式为 C9H18O5S ，分子量为 238.30 。

-IPTG, cell growth

+IPTG, target gene expression

Induced Expression of Gene

• Physical---λPL and temperature sensitive(λcI875 lysogen,32 ,42℃ ℃)

Induced Expression of GenePromoter: λPLλPR Terminator: rrnBT1T2Supression: 32 Gene expression: ℃ 42 ℃

Transcription

and Translation

in SV40 Virus

SV40 Virus Vector

SV40 Virus

Vector and

COS Cells

Expression Vectors for Mammalian Cells

Gene Expression

in Mammals