DNA, RNA and Protein

DNA, RNA and Protein

Translation How the Genetic Information Is Used to Build a Protein Information Flow From DNA replication DNA transcription initial transcript RNA processing

mature RNA translation Protein Properties of the Genetic Code Triplet 3 nucleotides code for 1 amino acid Non-overlapping Codons are adjacent to each other

Degenerate Some amino acids have more than one codon Almost universal A few exceptions occur in mitochondrial, bacterial and protist genes 53 Sequence of CODONS Accurate Protein Synthesis Depends

on Codon-Anticodon Recognition tRNA Charging A specific tRNA synthetase catalyzes the attachment of the appropriate amino acid to each tRNA Energy from conversion of ATP to AMP drives the reaction Overview of Translation At the ribosome, codons in mRNA are recognized by tRNA anticodons to place

amino acids in the specific sequence determined by the DNA. Three Stages of Translation: Initiation- assemble components to start process Elongation- add amino acids in repeated cycles Termination- release protein product Initiation (Prokaryotic) Formation of initiation complex containing: Small ribosomal subunit mRNA Initiator (f-Met) tRNA

Large ribosomal subunit f-met UAC 5-------------AUGUUUCUCUGA---3 mRNA Elongation a. next tRNA binds to mRNA at the A site E site P site A site

f-met phe UAC AAA 5 -------------AUGUUUCUCUGA---3 mRNA Elongation b. amino acids are joined with peptidyl transferase peptide bond f-met phe UAC AAA

5-------------AUGUUUCUCUGA---3 mRNA Elongation c. ribosome moves by one codon (translocation) --growing peptide is now in P site --first tRNA is in E site f-met phe

UAC AAA 5-------------AUGUUUCUCUGA---3 mRNA Elongation d. first tRNA is released from E site UAC f-met

phe AAA 5-------------AUGUUUCUCUGA---3 mRNA Elongation (second cycle) a. next tRNA binds to mRNA at the A site f-met UAC

phe leu AAA GAG 5 -------------AUGUUUCUCUGA---3 mRNA Elongation (second cycle) b. amino acids are joined with peptidyl transferase peptide bond

UAC f-met phe leu AAA GAG 5 -------------AUGUUUCUCUGA---3 mRNA

Elongation (second cycle) c. ribosome moves by one codon --growing peptide is now in P site --second tRNA is now in E site UAC f-met phe leu

AAA GAG 5-------------AUGUUUCUCUGA---3 mRNA Elongation (second cycle) d. second tRNA is released from E site UAC f-met

phe leu AAA GAG 5-------------AUGUUUCUCUGA---3 mRNA Termination a. release factor binds to stop codon

UAC AAA f-met phe leu RF

GAG 5-------------AUGUUUCUCUGA---3 mRNA Termination b. protein chain is released other components separate UAC f-met phe leu

GAG Large Subunit RF AAA 5-------------AUGUUUCUCUGA---3 Small Subunit

mRNA Applying Your Knowledge If the mRNA sequence for codons 5, 6, and 7 of a protein is 5-AAG-AUU-GGA-3, what is the amino acid sequence in the protein? 1. Gly-ile-lys 2. Arg-leu-glu 3. Glu-leu-arg 4. Asn-met-gly 5. Lys-ile-gly

Control of Initiation in Prokaryotes A. Small Ribosomal Subunit binds to mRNA a. IF-3 binds to small ribosomal subunit b. Small ribosomal subunit binds to Shine-Dalgarno sequence on mRNA A sequence in the 16S rRNA of the small ribosomal subunit is complementary to the Shine-Dalgarno sequence on mRNA IF-3 = Initiation Factor 3

Control of Initiation in Prokaryotes B. Formyl-methionine tRNA binds to mRNA a. IF-2 +GTP + f-met-tRNA join b. f-met-tRNA binds to the first codon c. IF-1 joins to small subunit d. IFs dissociate, GTP is hydrolyzed to GDP C. Large Ribosomal Subunit binds to mRNA Control of Initiation in Eukaryotes Binding of Small Subunit assisted by proteins bound to -5-methyl guanine cap

-Poly-A tail Control of Elongation by Elongation Factors EF-Tu joins GTP and a charged tRNA to form a complex that binds to the A site EF-Ts regenerates the EF-Tu + GTP

complex EF-G and GTP are required for ribosome translocation Control of Termination by Release Factors RF1 binds to UAA and UAG RF2 binds to UAA and UGA RF3 forms a

complex with GTP that binds to the ribosome Energetics of Translation Number of Phosphate Bonds Required (use of ATP or GTP) Initiation 1 for assembly of ribosomal subunits 2 for activation of f-met tRNA

Elongation 2 for activation of each tRNA 2 for addition of each amino acid Termination 1 for dissociation of ribosomal subunits Energetics of Translation How many phosphate bonds are required to build a protein of 100 amino acids?

First Amino Acid Next 99 Amino Acids Termination Total 3 99x4=396 1 400

Recently Viewed Presentations

  • Diversifying your business with woodland creation Douglas Priest,

    Diversifying your business with woodland creation Douglas Priest,

    wood for on-site boiler. Alternative income stream, both grants and timber. Succession planning. Tax Benefits. Growing asset which adds value to farm. No income tax on timber sales or grants. No capital gains tax on the growth in value of...
  • Name title - Leicester`s Research

    Name title - Leicester`s Research

    In collaboration with Dr Linda Barton, Consultant Haematologist &Lara CresswellFRCPath, Clinical Lead for Molecular Diagnostics, UHL. A Precision Medicine Cohort goes Multi-ethnic: enhancing medicines discovery in South Asians using EXCEED - Dr Catherine John, Dr Nicola Reeve, Dr Chiara Batini...
  • Reducing Recidivism: Serious and Violent Youth

    Reducing Recidivism: Serious and Violent Youth

    RNR (Andrews, Bonta and Hoge, 1990) Risk—what places this youth at risk of further crime. Needs—what needs does the youth have (education, health, etc.).
  • A Brief History of Planetary Science

    A Brief History of Planetary Science

    --Webster's Dictionary 1913 What is Physics? Physics is a way of figuring out how things work More specifically: what are the underlying rules that govern how things work? We will deal mostly with classical physics: i.e. How did things work...
  • Sensory Imagery - The year 9 ENGLISH Journey

    Sensory Imagery - The year 9 ENGLISH Journey

    Sensory Imagery Sight, Sound, Smell, Taste, and Touch The FIVE Senses Sight—visual imagery Sound—auditory imagery Touch—tactile imagery Smell—olfactory imagery Taste—gustatory imagery Sight "Her head nodded and her wrists were active, showing off the jingling bracelets she had bought at the...
  • Risk of biliary tract injury during laparoscopic surgery

    Risk of biliary tract injury during laparoscopic surgery

    Risk of biliary tract injury during laparoscopic surgery. By. Dr Fadhl Ali Almohtady. Consultant Surgeon . ... Mechanical trauma can have similar effects. Lahey Clinic, Burlington, MA.1994 ... Risk of biliary tract injury during laparoscopic surgery
  • Advanced manufacturing Lab, Industrial Enginnering Dep ...

    Advanced manufacturing Lab, Industrial Enginnering Dep ...

    with a supervisor. Microsoft offers Netmeeting on its network which. makes it possible to coordinate work on PCs in different locations. CU-SeeMe is a. program developed at Cornell. It is free and lets users on the Internet set up small....
  • Types of Writing So, what do I write?

    Types of Writing So, what do I write?

    These purposes can be grouped under types of writing. Types of Writing . Narrative. Descriptive. Expository. Persuasive. Creative *Note: These writing types can overlap. Narrative Writing. recounts a personal experience in the form of a story and always includes characters,...