Intron prevalence 100 90 80 70 60 口 Yeast 50 Fungi amma 10
Intron Prevalence 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 100 0 1 > 1 Yeast Fungi Mammal
Intron size Exon size 70 60 0 50 20 30 20 10 ≤100<200 5 100200-300->500 k b 100200300500 口 Fungi ■ Vertebrate
Intron Size 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 <100 <200 < 1 kbp 1 to 5 > 5 Fungi Verterbrate Exon Size 0 5 1 0 1 5 2 0 2 5 3 0 3 5 1 - 100 100- 200 200- 300 300- 500 >500 Fungi Verterbrate 0 5 1 0 1 5 2 0 2 5 3 0 3 5 1 - 100 100- 200 200- 300 300- 500 >500 Fungi Verterbrate
TATA box as a promoter of transcription initiation TATA box mRNA starts A2116491095679752411624 A=50% G=25% Ba ase c23391000000093537 C,U≈25% frequency (%) G283530000312403830 T281083910053303610119 Transcription T A TA G 3 Consensus sequence to-25 Characterization of promoters in 900 different eukaryotic protein coding genes reveals consensus sequence of TATA box. Mutations between TATA and transcription start have little to no effect, shortening of linker region forces transcription initiation further downstream' Alternative to TATA box is initiator element(degenerate)and CpG islands (20-50 nts within 100 nts of start)
Eukaryote promoter Goldberg- Hogness or TATA located at-30 Additional regions at-100 and at-200 Possible distant regions acting as enhancers or silencers(even more than 50 kb) mRNA GGGCGG CCAAT TATA 200bp ~100bp
Eukaryote Promoter • Goldberg-Hogness or TATA located at –30 • Additional regions at –100 and at –200 • Possible distant regions acting as enhancers or silencers (even more than 50 kb)
Basal Promoter Analysis ATATAA 30 TBP GGCCAATC 75 CTENF1 GCCACACCC-90 SP1 +1 GC CAAT TATA
Basal Promoter Analysis • ATATAA -30 TBP • GGCCAATC -75 CTF/NF1 • GCCACACCC -90 SP1 GC CAAT TATA +1