70 likes | 204 Views
Strategy of Redesign for CTLMA2 Target Site. AniI WT: T GA G G AG GTT TC TCTGT A AA || | ||| ||||| || CTLMA2 : A GA A G CC GTT CA TCTGT C AA. Saturation mutagenesis / Random mutagenesis. Mutagenesis based on Rosseta design.
E N D
Strategy of Redesign for CTLMA2 Target Site AniI WT: TGAGGAGGTTTCTCTGTAAA || | ||| ||||| || CTLMA2 : AGAAGCCGTTCATCTGTCAA Saturation mutagenesis / Random mutagenesis Mutagenesis based on Rosseta design Semi-saturation mutagenesis based on the X-tal structure +1C/+2A/+8C -5C/-4C -7A Semi-saturation mutagenesis to promote the catalysis Semi-saturation mutagenesis based on the X-tal structure Random mutagenesis -10A/-7A -5C/-4C Semi-saturation mutagenesis to optimize the catalysis CTLMA2 site -10A/-7A/-5C/-4C
AniI WT: TGAGGAGGTTTCTCTGTAAA || | ||| ||||| || CTLMA2 : AGAAGCCGTTCATCTGTCAA G : C A : T Redesign for -7A T29 T22 R72 K23 -7G >-7A -7C >-7T (Gray, WT target; magenta, CTLMA2 target) Introduced mutations at T22, K23 and T29, in order to alter the contact with the bottom strand base at the position -7.
pEndo HE Selection for -7A Transformation Amino-acid substitutions F, L, I, V, Y, H, N, D, C, R, S, and G at T22 and T29 M, P, T, A, Q, K, E, W, F, L, I, V, Y, H, N, D, C, R, S, and G at K23 pCcdB Target + Arabinose Induction of HE gene 15 h Induction of both HE and CcdB genes + Arabinose + IPTG Data from 2 independent experiments T22Y/K23G/T29S was chosen for the next selection (-10A/-7A).
Redesign for -10A/-7A AniI WT: TGAGGAGGTTTCTCTGTAAA || | ||| ||||| || CTLMA2 : AGAAGCCGTTCATCTGTCAA K26 Y27 G25 K24 -10T >-10A T29 > S29 T22 >Y22 K23 >G23 -10T >-10A -10A >-10T -7A -7T -10A >-10T (Gray, WT target; magenta, CTLMA2 target) Introduced mutations at K24, G25, K26, and Y27 in Y2 + T22Y/K23G/T29S background.
Redesign for -5C/-4C AniI WT: TGAGGAGGTTTCTCTGTAAA || | ||| ||||| || CTLMA2 : AGAAGCCGTTCATCTGTCAA A68 G33 Y18 E31 R59 S20 -5G > -5C -5G >-5C -4G > -4C -4G >-4C (Gray, WT target; magenta, CTLMA2 target) Introduced mutations at Y18, S20, E31, G33, R59 and A68, based on Rossetta design.
pEndo HE Selection for -5C/-4C Amino-acid substitutions S and Y at Y18; Q, K and S at S20; R, S, Q, A and E at E31; S, R and G at G33;F, L, I, V, H, N, D, C, R, S, G, and Y at R59; T, R, I, and S at A68 Transformation pCcdB Target + Arabinose Induction of HE gene 24 h Induction of both HE and CcdB genes + Arabinose + IPTG * Mutation induced through PCR amplification Data from 2 independent experiments G33R/V56I/R59S/A68R was subjected to the next selection to promote the cleavage activity.
Redesign for -5C/-4C (2nd round) V56 > I56 I55 A68 >R68 S57 G33 > R33 E35 R59 >S59 -5G > -5C -4G > -4C (Gray, WT target; magenta, CTLMA2 target) Introduced hydrophilic residues at E35, I55, S57 and S59.