10.1 Introduction T he cis acting cp er ato r/prom ce r sites are a da ce nt tot he str ud ural genes Figure 10.2 In Regul atory region Strucural gene(s negative control, 八 M a trans-acting Genes are on because RN Polymerase initiates transcr ption at prom oter repressor binds to the cis-acting operator to turn off transcription RNA n prokaryotes, ySeveralp rc eins p° multiple genes are controlled Genes are tumed off when repressor binds to ope rator coordinate Repressor 消当
Figure 10.2 In negative control, a trans-acting repressor binds to the cis-acting operator to turn off transcription. In prokaryotes, multiple genes are controlled coordinately. 10.1 Introduction
10.1 Introduction Regulatory region prom oter Startpoint Structural genes Prom oter GENE OFF BY DEF AULT AAAAAAAAAAAAAAA RNA Factors int erad wth rNa pol ym erase GENE TURNED ON BY ACTIVATORS 八AA RNA www' Single protein Figure 10. 3 In positive control, trans-acting factors must bind to cis-acting sites in order for RNa polymerase to initiate transcription at the promoter In a eukaryotic system, a structural gene is controlled individually 请莘大
Figure 10.3 In positive control, trans-acting factors must bind to cis-acting sites in order for RNA polymerase to initiate transcription at the promoter. In a eukaryotic system, a structural gene is controlled individually. 10.1 Introduction
10.2 Structural gene clusters are coordinately controlled Operon is a unit of bacterial gene expression and regulation, including structural genes and control elements in DNA recognized by regulator gene product(s). 消当
Operon is a unit of bacterial gene expression and regulation, including structural genes and control elements in DNA recognized by regulator gene product(s). 10.2 Structural gene clusters are coordinately controlled
10.2 Structural gene clusters are coordinately controlled PO 闷 DAAAAAAAAAAAAAA 104082 3510 780 825 mRNA Protein Repressor 阝 galactosidase Permease ransacetyase Figure 10.4 The lac operon occupies 6000 bp of DNA. At the left the lacl gene has its own promoter and terminator. The end of the lacl region is adjacent to the promoter, P. The operator, O occupies the first 26 bp of the long lacz gene, followed by the 请莘大 lacy and laca genes and a terminator
Figure 10.4 The lac operon occupies ~6000 bp of DNA. At the left the lacI gene has its own promoter and terminator. The end of the lacI region is adjacent to the promoter, P. The operator, O, occupies the first 26 bp of the long lacZ gene, followed by the lacY and lacA genes and a terminator. 10.2 Structural gene clusters are coordinately controlled
10.2 Structural gene clusters are coordinately controlled Startpoint WNN Figure 10.5 Urw indie Repressor and RNa polymerase 5040-30-20-101102030 bind at sites that Promoter overlap around binds RNa polymerase the startpoint of Operator the lac operon binds repressor 请莘大
Figure 10.5 Repressor and RNA polymerase bind at sites that overlap around the startpoint of the lac operon. 10.2 Structural gene clusters are coordinately controlled