1. UVA (kJ/m 2 ) UVB (J/m 2 ) UVC (J/m 2 ) 0 50 100 200 50 100 200 5 10 20 Supplementary Figure S1 Gel loading control for carbonyl visualization Extracts (20 µg) prepared from HaCaT cells irradiated with UVA, UVB or UVC as indicated were separated by PAGE and stained with coomassie blue. The remaining extract was derivatized with Hydroxylamine Alexa Fluor 647 and separated by PAGE for protein carbonyl visualization (Figure 1B)

2. Supplementary Figure S2 HaCaT cell survival as a function of CPDs The number of photoproducts was calculated based on a value for 254 nm of 2.3 CPD/10 8 Da/J/m 2. Doses of UVC (7 J/m 2 ), UVB (300 J/m 2 ), and UVA (300 kJ/m 2 ) that induced equal numbers of CPDs in HaCaT cells were determined experimentally by ELISA. Survival data are mean values for two determinations CPDs/10 8 Da Survival (%)

3. 200kJ/m 2 6:4 Py:Py removed (%) 0 kJ/m 2 Supplementary Figure S3 HeLa cells were irradiated with 200 J/m 2 UVB and UVA as indicated. DNA was extracted at the times shown and 6:4 Py:Pys were measured by ELISA. Data from two independent experiments. NER in UVA-treated HeLa cells

4. U2OS + UVA U2OS RPA21 + UVA RPA21 Time after UVB irradiation (h) 6:4 Py:Py removed (%) Supplementary Figure S4 U2OS and RPA overexpressing U2OS-RPA21 cells were irradiated with 200 J/m 2 UVB ± 200 kJ/m 2 UVA as indicated. DNA was extracted at the times shown and 6:4 Py:Pys were measured by ELISA. Data from two independent determinations. RPA overexpression in U2OS-RPA21 cells protects NER against inhibition by UVA

5. Supplementary Figure S5 The effect of IDH R132 inhibition on NER in HT1080 chondrosarcoma cells A B HaCaT cells were grown in the presence or absence of the R132 IDH inhibitor AGI-5198 (800 nM) for 72 h before irradiation with 150 kJ/m 2 UVA. aNADPH levels were measured 30 min after UVA treatment. Levels in non drug-treated, unirradiated control cells were set to 100%. bDNA 6:4 Py:Pys were measured by ELISA 4h after irradiation. Mean values from two experiments 6:4 photoproducts removed (%) 0 25 50 UVB + UVA UVB UVB + AG15198 UVB + UVA + AG15198 75 NADPH (% control) Control (untreated) UVA + AGI5198 Control + AGI5198 UVA A