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Breu TATA Bred INR MTE DPE 3’ - 40 - 31/30 +1 +18-27 +28-33 CAP 5510: Introduction to Bioinformatics CGS 5166: Bioinformatics Tools Professor Giri Narasimhan ECS 254; Phone: x3748 [email protected] www.cis.fiu.edu/~giri/teach/BioinfF18.html 9/10/18 CAP5510 / CGS 5166 !1 CAP 5510: Introduction to Bioinformatics CGS 5166: Bioinformatics Tools Professor Kalai Mathee BSc (Genetics), MSc (Molecular Biology), PhD 1992 (Microbiology & Immunology), MPH 2018 (Health Policy & Management) AHC4 - 225; Phone: x0628 [email protected] www.faculty.fiu.edu/~matheek 9/10/18 CAP5510 / CGS 5166 !2 Session Learning Objectives ❑ Central Dogma ❑ Gene Regulation ❑ Transcriptional Unit Single Prokaryotic Multigene ➢ Operon ➢ Regulon ➢ Promoter ❑ Gene Expression ➢ Operator ❑ ➢ Enhancer etc Tools to study gene Eukaryotic expression ➢ TATA Box Single gene ➢ UAS Multi gene ➢ Silencer Genome-dependent ➢ Insulator etc Genome-independent 9/10/18 CAP5510 / CGS 5166 !3 Why Should You Care? ❑ Promoter Prediction Methods https://scholar.google.com/scholar? q=promoter+prediction+methods&hl=en&as_sdt=0&as_vis=1&oi =scholart ❑ Gene Prediction Methods https://scholar.google.com/scholar? hl=en&as_sdt=0%2C10&as_vis=1&q=gene+prediction+methods &btnG= ❑ Gene Expression Analysis https://scholar.google.com/scholar? hl=en&as_sdt=0%2C10&as_vis=1&q=gene+expression+bioinfor matic+methods&btnG= ❑ Sequence and Genome Analyses https://scholar.google.com/scholar? 9/10/18 hl=en&as_sdt=0%2C10&as_vis=1&q=Sequence+and+genome+anCAP5510 / CGS 5166 !4 alysis+&btnG= Central Dogma Francis Crick (1916 - 2004) ❑ Nobel Prize — 1962 Med ❑ Central Dogma — 1958 9/10/18 CAP5510 / CGS 5166 !5 Paradigm Change Howard M Temin David (1934 - 1994) Baltimore (1938 - ) ❑ Nobel Prize — 1975 Med ❑ Reverse Transcriptase 9/10/18 CAP5510 / CGS 5166 !6 Central Dogma 9/10/18 CAP5510 / CGS 5166 !7 Transcription ❑ Process by which a selected segment of DNA corresponding to a gene is used to synthesize an RNA molecule ❑ Catalyzed by an enzyme called DNA-dependent RNA polymerase - (RNAP) ❑ Gene ❑ Open Reading Frame (ORF) ❑ https://www.youtube.com/ watch?v=cXlv21NCGxQ ❑ https://www.youtube.com/ watch?v=DKgJPhvCDU8 9/10/18 CAP5510 / CGS 5166 !8 Transcription σ Initiation σ Termination Elongation NusA NusA 9/10/18 CAP5510 / CGS 5166 !9 Basic Transcription Components ❑ Prokaryotes (Eubacteria) ❑ RNAP Core — 2α, β, β’, ω ❑ RNAP Holoenzyme — Core + σ 9/10/18 CAP5510 / CGS 5166 !10 Eubacterial RNAP Gene Product Subunits Function Enzyme assembly α subunit α α rpoA Promoter recognition 40 kD Binds some activators β subunit rpoB β 155 kD Catalytic center β’ subunit rpoC β’ } 150 kD ω subunit ω rpoZ RNAP assembly 10 kD σ subunit rpoD σ Promoter specificity 32-90 kD Binds to -10 and -35 α β Core enzyme σ ω α β’ 9/10/18 Holoenzyme !11 Genes/ORF – Eubacteria ❑ Start codon AUG [DNA: ATG] ➢ Met or Modified Met (fMet) ➢ 83% GUG [DNA: GTG] Start Stop ➢ 14 % Codon Codon UUG [DNA: TTG] ➢ 3 % ❑ Stop/Termination codons (3) 5’ 3’ UAG [DNA: TAG] — Amber UAA [DNA: TAA] — Ochre UGA [DNA: TGA] — Opal ❑ Almost universal Exception — Mitochondria 9/10/18 CAP5510 / CGS 5166 !12 Eubacteria Transcription Unit Start Stop Codon Codon 5’UTR ORF 3’UTR +1 5’ Terminator 3’ -35 -10 RBS RNA-coding region Promoter Transcription start site ❑ Do eubacteria have introns? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC177115/pdf/1773897.pdf ❑ Transcription start site has to be verified ! +1 ❑ +1 Start to the start codon ❑ Region upstream: Promotor (negative value) 9/10/18 CAP5510 / CGS 5166 !13 Basic Promoter — Eubacteria Promoter 5’UTR +1 5’ 3’ -35 -10 Transcription start site ❑ Recognized by the house keeping sigma factor E. coli σ70 ❑ Specific sequence -10 — TATAAT -35 — TTGACA Spacing — 17 +/- 1 bp 9/10/18 CAP5510 / CGS 5166 !14 Alternate Sigma Factors Promoter 5’UTR +1 5’ 3’ -24 -12 Transcription start site ❑ Many in each bacteria ❑ Different -10 and -35 ❑ Different location altogether ❑ RpoN or σ54 -12 and -24 9/10/18 CAP5510 / CGS 5166 !15 Promoter — Eubacteria Promoter +1 5’ 3’ -44 -35 -10 Enhancer Element Transcription start site ❑ Enhancer element – promotes transcription ❑ Highly expressed genes 9/10/18 CAP5510 / CGS 5166 !16 Activator Binding Sites Promoter +1 5’ 3’ -44 -35 -10 II II I Transcription start site ❑ Activators — Positive regulators Activate transcription Sequence varies with the regulators ❑ Modulators 9/10/18 CAP5510 / CGS 5166 !17 Repressor Binding Sites Promoter +1 5’ 3’ -44 -35 -10 IV III II I Transcription start site ❑ Repressors Negative regulators Prevent transcription ❑ Operator sites 9/10/18 CAP5510 / CGS 5166 !18 Regulatory Elements ❑ Genes ❑ Cis Elements Regulator Promoters Structural Operators ❑ Trans Elements/Transacting factors Diffusible Repressors Activator lac operon PlacI Plac Olac P P O lacI lacZ lacY lacA Regulator Gene Structural Genes 9/10/18 CAP5510 / CGS 5166 !19 Promoter — Eubacteria 9/10/18 CAP5510 / CGS 5166 !20 Mature RNA — Eubacteria Transcriptional unit RBS ORF +1 5’ Terminator 3’ -35 -10 Promoter RNA-coding region Transcription start site Start Stop mRNA Codon Codon 5’ 3’ RBS Protein-coding region RBS Ribosome 5’ untranslated region 3’ untranslated region binding site 5’ UTR 3’ UTR Leader Trailer 9/10/18 CAP5510 / CGS 5166 !21 Cistron — Mono vs Poly Transcription start site Promoter RNA-coding region ORF +1 RBS 5’ Terminator 3’ -35 -10 ❑ Transcriptional unit - Single gene operon Promoter RNA-coding region +1 ORF1 ORF2 5’ Terminator 3’ -35 -10 ❑ Transcriptional unit - Two-gene operon ❑ Under the control of single promoter 9/10/18 CAP5510 / CGS 5166 !22 Regulon ❑ A group of operons regulated as a unit ❑ Modulator Repressor Activator ❑ Consensus binding site DtxR Box https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3022926/ 9/10/18 CAP5510 / CGS 5166 !23 LexA Regulon https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3022926/ 9/10/18 CAP5510 / CGS 5166 !24 Complex Regulation Tatke, Mathee et al 2017 9/10/18 CAP5510 / CGS 5166 !25 Coupling 9/10/18 CAP5510 / CGS 5166 !26 Eukaryotic RNAPs ❑ Three: RNAPI, RNAP II and RNAP III ❑ Multisubunit ❑ RNAP I Exclusive to ribosomal RNA (28S, 18S & 5.8S) ❑ RNAP II Most of the genes in eukaryotes Respond to environmental cues ❑ RNAP III Short non-coding RNAs such as tRNAs, 5S rRNA, U6 snRNA & a limited number of others 9/10/18 CAP5510 / CGS 5166 !27 Core Promoter — Eukaryote 5’ BREu TATA BREd INR MTE DPE 3’ - 40 - 31/30 +1 +18-27 +28-33 ❑ TATA box ❑ BRE – Transcription factor IIB Recognition Element ❑ INR — Initiator ❑ MTE — Motif Ten Element ❑ DPE — Downstream Promoter Element https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1219314/ https://epd.vital-it.ch/index.php 9/10/18 CAP5510 / CGS 5166 !28 Basic Promoter — Eukaryote 5’ Silencer BREu TATA BREd INR MTE DPE 3’ - 40 - 31/30 +1 +18-27 +28-33 ❑ TATA box ❑ UAS — Upstream activator sequence ❑ Silencer + 100-200 bp upstream of TATA box Position independent https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1219314/ https://epd.vital-it.ch/index.php 9/10/18 CAP5510 / CGS 5166 !29 Complex Promoter — Eukaryote ❑ Silencer & Insulator — 10 to 50 kb US/DS ❑ NRE — Negative Regulatory Sequence Position-dependent https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830304/ http:// genesdev.cshlp.org/content/16/3/271.full 9/10/18 CAP5510 / CGS 5166 !30 RNAPII — Core Promoter W — A & T RNAP II S — C & G Y — C & T TAFII40 TFIIA150 TAFII110 TAFIID R — A & G TAFII60 MTE – motif ten element TBP TFIIB 5’ BREu TATA BREd INR MTE DPE 3’ - 31/30 +1 +18-27 +28-33 SSRCGCC TATAWAAR RTDKKK YYANWYY CGANCCGG WYGT https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4214234/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830304/ 9/10/18 CAP5510 / CGS 5166 !31 RNAPIII — Promoter RNAP III Brf TCF5 TFC4 TCF3 TBP TFCI 5’ BREu TATA BREd A Box B Box Term 3’ TRGYNNARNNG RTTCRANYY TTTTT https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4214234/ 9/10/18 CAP5510 / CGS 5166 !32 Promoter Start Sites ❑ Nobel Prize — 1975 Med ❑ Reverse Transcriptase ❑ Primer Extension Analysis ❑ RNA Sequencing ❑ Initiated vs processed RNA Howard M Temin David (1934 - 1994) Baltimore (1938 - ) ORF -60 -50 -40 -30 -20 -10 +10 +1 A/G 9/10/18 CAP5510 / CGS 5166 !33 Binding ❑ Gel Shift Assay Retardation assay Probe - Protein Probe Cra-Dependent Transcriptional Activation of the icd Gene of Escherichia coli J. Bacteriol. 1999 181: 893-898 9/10/18 CAP5510 / CGS 5166 !34 Binding Sequence ❑ Footprinting Cra-Dependent Transcriptional Activation of the icd Gene of Escherichia coli J. Bacteriol. 1999 181: 893-898 9/10/18 CAP5510 / CGS 5166 !35 mRNA Capping ❑ Capping occurs during transcription https://en.wikipedia.org/wiki/Five-prime_cap 9/10/18 CAP5510 / CGS 5166 !36 PolyA-Tailing ❑ Adding of string of As to the tail of RNA https://www.youtube.com/watch?v=DoSRu15VtdM ❑ It can go up to ~250 As ❑ Template independent ❑ Prior to splicing https://www.slideshare.net/DeeshmaKp/8-rna-types-85710809 9/10/18 CAP5510 / CGS 5166 !37 RNA Processing pre- mRNA Cap Tail ❑ mRNA is capped and tailed ❑ Spliced Spliced junction promotes diversity in some genes ❑ mRNA moves out of nucleus to cytoplasm https://fr.m.wikipedia.org/wiki/Fichier:DNA_exons_introns.gif 9/10/18 CAP5510 / CGS 5166 !38 Why Regulate? ❑ Control the quantities of gene products Some are needed in large quantities: Ribosomes Some are needed in small quantities: Enzymes ❑ Synthesize when the need arises (inducible) Respond to environment, eg., heat shock, UV radiation ❑ Need for temporal expression Phage development Growth ❑ Internal flexibility Provides adaptability 9/10/18 CAP5510 / CGS 5166 !39 Types of Regulation ❑ Constitutive Unregulated (housekeeping genes) ❑ Inducible Basal levels ! Induced in response ❑ Repressible Normal levels ! Repressed in response to signal ❑ Temporal Growth, phage ❑ Coordinated Regulation Several products that act in a single pathway 9/10/18 CAP5510 / CGS 5166 !40 Points of Regulation From genotype to phenotype Replication DNA Transcription mRNA Translation Protein Post- Post-translational transcriptional Regulation Regulation 9/10/18 CAP5510 / CGS 5166 !41 Gene Expression ❑ Promoter fused with a reporter Reporters: lacZ, lux, GFP etc https://en.wikipedia.org/wiki/Reporter_gene 9/10/18 CAP5510 / CGS 5166 !42 Gene Expression in E.
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