Lecture 8 ·88 Attenuation 8. 9 Other global control networks 8. 10 Signal Transduction and Two Component Regulatory Systems 8.11 Regulation of Chemotaxis
Lecture 8 • 8.8 Attenuation • 8.9 Other Global Control Networks • 8.10 Signal Transduction and TwoComponent Regulatory Systems • 8.11 Regulation of Chemotaxis
RNA and termination RNA: single stranded nucleic acid can form secondary structures Rho-dependent termination: protein signal Rho-independent signal: hairpin or stem loop Rna structure, followed by several uracil
RNA and termination • RNA: single stranded nucleic acid – can form secondary structures • Rho-dependent termination: protein signal • Rho-independent signal: hairpin or stemloop RNA structure, followed by several uracils
TGCGGGTCGACTGICCGATICAGTCGACCITTT DNA with ACGCICCAGCTGACGGCTAGTCAGCTGGAAAA inverted repeats Transcription of one strand UGCGGGUCGACUGCCGAUCAGUCGACCUUUU RNA Fold to form secondary structure UGCGY UUUU GGUC C A Stem-loop in RNA immediately upstream from a run of uracils leads to terminati UIA of transcription G C G
Tryptophan Operon PO L trpE trpD trpC trpB trpA Leader Met-Lys-Ala-Ile-Phe-Val-Leu-Lys-Gly-Trp-Trp-Arg-Thr-Ser Threonine Met-Lys-Arg-lle-Ser-Thr-Thr-lle-Thr-Thr-Thr-lle-Thr- lle-Thr-Thr-Gly-Asn-Gly-Ala-Gly Histidine Met-Thr-Arg-Val-GIn-Phe-Lys-His-His-His-His His-His-His-Pro-Asp Phenylalanine Met-Lys-His-lle-Pro-Phe-Phe-Phe-Ala-Phe-Phe- Phe-Thr-Phe-Pro Figure 8.20
Figure 8.20 Tryptophan Operon
Tryptophan Operon: mRNA 4 trpD→ regions 1, 2: synthesis of leader peptide regions 2, 3: form stem-loop structure regions 3, 4: form stem-loop structure
Tryptophan Operon: mRNA 1 2 3 4 trpE → • regions 1, 2: synthesis of leader peptide • regions 2, 3: form stem-loop structure • regions 3, 4: form stem-loop structure