Chemical Biology 03! Oct 16, 2009! Central Dogma –III! and mutation! Transcription temporary intermediate (“messenger”) Translation plasm! cyto flow of information in ALL cellular organisms = “the Central Dogma” in Eukaryotes 1o transcript (“pre-mRNA”) Processing of messenger RNA • at the 5’ end • at the 3’end • in the middle mature mRNA ready for translation CAP is added to 5’ end and TAIL is added to 3’ end of each mRNA mRNA! 5’! 3’! Necessary for message stability And identification as a messenger RNA! "#$! %&'()*&+,%+-(! ,&-%.+(!%&'()/'%+-(! introns intervening sequences Splicing expressed sequences - remove introns exons - rejoin exons protein translation β Globin primary transcript is 2000 nucleotides long ! Splicing protein translation β Globin polypeptide is 147 amino acids long Arrangement of exons and introns in two human blood genes in Eukaryotes 1o transcript (“pre-mRNA”) Processing of messenger RNA • at the 5’ end • at the 3’end • in the middle mature mRNA ready for translation Ribosome = Protein Factory last week’s Nobel Prize (Chem): studies that unveiled the structure &function amino acids are assembled of the ribosome: according to order specified by Venkatraman Ramakrishnan (UK), messenger RNA Tom Steitz (U.S.), Ada Yonath (Israel) Ribosome is enormous (complex of >80 proteins & 4 RNA molecules) Typical cell has millions of ribosomes! Adapter Molecules make the correlation between codon and amino acid: tRNA (transfer RNA) tRNA ! #0! 01! #0! 01! #0! 01! ”reads” codon (triplet of nucleotides in mRNA)! .%*5! 23#$4!!!A-U-G - C-U-G -G-U-G-G-A-U-C-C-U-G-G-A-U-U-C tRNA (transfer RNA) ~80 nte single stranded RNA molecule '(%+*-8-(! 67! -UCGGUAACUUGUACACC- 97! !"#$% *-8-(! The GENETIC CODE to Translate from RNA to PROTEIN: triplet code: set of 3 nucleotides (“codon”) encodes 1 amino acid ! ! ! !:2,-&%'(*.!-;!3.'8+(<!=&'2.! %A.!*'%!'%.!%A.!B@<! <.(.%+*!*-8.!+)!#>?!,@(*%@'%.8 !%A.*'%'%.%A.B@<! %!A.*!'%'!%.%!A.B!@<! ! ! ! ! ! ! ! !! %A!.*'!%'%!.%A!.B@!<! #-%.!&!,-))+B/.! &.'8+(<!;&'2.)!;-&!'(F! <+G.(!)%&.%*A!-;!3#$! -(/F!-(.!<+G.)!8.)+&.8!,&-%.+(! C-D!+)!&.'8+(<!;&'2.!*A-).(E! C-D!+)!&.'8+(<!;&'2.!2'+(%'+(.8E! Reading Frame is established by first AUG codon ( = START) 5’-A-C-G-U-A-U-G-C-A-U-U-U-G-A-C-G-U-A-A-3’ “gene” Segment of DNA that encodes a product (includes sequences that Do not directly code for a.a.)! H@I'&F-%.)! Mutation = change to DNA Caused by: errors in DNA Replication toxic chemicals (mutagens) other environmental abuse such as UV rays! How would change to DNA affect a gene product? ! H;;.*%!-;!)+(</.!(@*/.-%+8.!*A'(<.!+(!"#$!!JK!L,-+(%!2@%'%+-(MN4! TAC CGA TTC TTC CAA ATA CGG UAG GCU AAG AAG GUU UAU GCC met--ala--lys--lys---val--tyr---ala O').!P@B)%+%@%+-()! QP+/.( %!2@%'%+-(! TAC CGA TTC TTT CAA ATA CGG UAG GCU AAG AAA GUU UAU GCC met--ala--lys--lys---val--tyr---ala QR+)).().!2@% '%+-(! TAC CGA TTC TGC CAA ATA CGG UAG GCU AAG ACG GUU UAU GCC met--ala--lys---thr---val--tyr---ala Q#-().().!2@% '%+-(! TAC CGA TTC ATC CAA ATA CGG UAG GCU AAG UAG GUU UAU GCC met--ala--lys--stop =&'2.!PA+;%!2@%'%+-()!! J&.*'//!S'(-;)IF7)!D-&IN! TAC CGA TTC TTC CAA ATA CGG UAG GCU AAG AAG GUU UAU GCC "./.%+-()! 2.%00'/'00/F)000/F)000G'/00%F&000'/'! TAC CGA TTC TCC AAA TAC GGA :().&%+-()! UAG GCU AAG AGG UUU AUG CCU 2.%00'/'00/F)00/F)000,A.002.%00,&-! TAC CGA TTC TTT CCA AAT ACG UAG GCU AAG AAA GGU UUA UGC 2.%00'/'00/F)00/F)000</F00/.@000*F)!.