Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Lysine at 249 displaces 8-oxoGua from C1’ (arrow)H2NOglutamineH2NlysineC1'HUMAN MITOCHONDRDIAL URACIL GLYCOSYLASE (UDG), WITH GLYCOSIDIC LINKAGE HYDROLYZEDhuman alkyladenine glycosylase (AAG)complex with DNA modified by tricyclic base 1,N6-AdeNNNNNdR1,N6-dAdoHolliday junctionEukaryotic homologues to RecA are characterized in yeast: DMC1 and RAD51BACTERIAL REPAIR BY RECOMBINATIONpol Error-prone extension of DNA from mispair opposite damagepol- Error-prone bypass of highly distorting or non-instructional lesionsE. coli UmuC/D (pol V)UmuC/Dpol-ηpol η complexed to cisplatin N7-cross linked GG: 3′ elongation steppol η complexed to cisplatin N7-cross linked GG: 5′ elongation stepNHNHOONHR'ROHNHNHOONHR'ROPO3- HO--CH(NH2)COOH TyrHO-CH2-CH(NH2)COOH SerHO-CH(CH3)-CH(NH2)COOH ThrEGF = epidermal growth factorMEK = mitogen activated protein kinase/extracellular signal regulated kinaseERK = extracellular regulated kinaseRelative transforming potency of mutations in codon 12 of Ras in NIH 3T3 cells Relative transforming potency of mutations in codon 12 of trout embryo Ras Transformation by mutation in codon 61 of trout embryo Ras mutation (B[a]P-induced) frequency aa substitution rel. transforming potency GGT TGT (G-C T- A transversion) 56% Gly Cys ? GGT GTT (G-C T- A transversion) 25% Gly Val 1.0 GGT GAT (G-C A- T transition) 19% Gly Asp 0.2 mutation (7,12-DMBA-induced) frequency aa substitution rel. taransforming potency GGA AGA (G•C A•T transition) 50% Gly Arg 1.0 GGA GTA (G•C T•A transversion) 50% Gly Val 0.6 mutation (7,12-DMBA-induced) frequency aa substitution rel. potency CAG CTG (A•T T•A transversion) 100% Gln Val ?effector binding loop 4active form of Ras, bound to GTP analogue inactive form of Ras, bound to GDP-CH2- replaces –O-loop 1loop 2loop 7Gly12Val mutant RasWT RasRas G12VRas G12PRas WT= Mg= H2OGln 61WT Ras, with Gln 61 highlightedRole of Gln 61 in GTPase activity of RASBAY 43-9006Phe467Phe467Val599Glu599P-loopP-loop(kinase domain – green)WT B-RafV599E B-RafKINASE ACTIVITY OF V599E