This pathway shows how all 45 different subunits are assembled into complex 1 (relevant for the electron transport chain, also known as OXPHOS system), which chaperones(visualised with a small circle and a "C') and which post-translational modifications (a dimethylation on NDUFS2 and hydroxylation on NDUFS7, both in the Q-module) are needed for this assembly. Most of the steps involved in this intricate process have been described in separate literature references, which have been combined in a review by Alba Signes and Erika Fernandez-Vizarra[https://doi.org/10.1042/EBC20170098]. If possible (based on the size of the protein in KD and available protein structures in Uniprot), the colour of the protein structure drawings have been matched to the annotated protein DataNodes. Abbreviations: IM, inner membrane; IMS, intermembrane space. df5 67 KD 12 KD ~12 KD 16.4 KD 22 KD 22 KD ~16 KD DMAC1/TMEM261 is implicated in the stabilization and/or assembly of the ND5-module 11,8 KD d45 Stabilising intermediated only lacking the N-module f32 cb9 d45 30.2 KDa (protein atlas) aka C3ORF1 Chaperone remains bound to the Q/ND1 subassembly until the last maturation steps. fe2 c23 52 Kda Chaperone DMAC1/TMEM261 is implicated in the stabilization and/or assembly of the ND5-module 11,8 KD d45 dbe d51 da8 b41 13.5 KD Stabilising intermediated only lacking the N-module f32 cb9 d45 8.1 KD Chaperone f38 e00 ca9 Not in Figure at first step, but written down in text! Chaperone f38 9.3 KD 67 KD 7 KD 15 Kd Not believed to be involved in catalysis 52 Kda 7 KD 15 Kd Not believed to be involved in catalysis d45 fe2 aka cV assembly factor e31 da8 f38 aka CIA30 e59 efe ffd aeb c6c 18 KD 11 KD 18 KD 11 KD Chaperone f38 e00 ca9 Chaperone ca9 e00 Chaperone f38 Chaperone e00 ca9 41KD 15KD 18 KD 11 KD 8.1 KD 41KD 15KD Not in Figure at first step, but written down in text! aka CIA30 e59 efe ffd aeb c6c 38.2 kDa seems to participate in the assembly of the Q-module necessary to maintain normal MT-ND1 synthesis fad 49 KD 49.2 kD (proteinatlas) 49 KD 23,7 KD The encoded protein(TYKY) contains two [4Fe-4S] ferredoxin consensus patterns [PMID: 9837812] b2c 20 kD Chaperone e14 30.2 KDa (protein atlas) 13.5 KD 49 KD 23,7 KD The encoded protein(TYKY) contains two [4Fe-4S] ferredoxin consensus patterns [PMID: 9837812] b2c 20 kD 38.2 kDa seems to participate in the assembly of the Q-module necessary to maintain normal MT-ND1 synthesis fad Chaperone Remain bound to this module until the final assembly steps Chaperone Remain bound to this module until the final assembly steps e14 20 kD 17 kD 30.2 KDa (protein atlas) 13.5 KD 49 KD 23,7 KD The encoded protein(TYKY) contains two [4Fe-4S] ferredoxin consensus patterns [PMID: 9837812] b2c 20 kD 38.2 kDa seems to participate in the assembly of the Q-module necessary to maintain normal MT-ND1 synthesis fad Chaperone Remain bound to this module until the final assembly steps Chaperone Remain bound to this module until the final assembly steps e14 aka C3ORF1 Chaperone remains bound to the Q/ND1 subassembly until the last maturation steps. fe2 c23 30.2 KDa (protein atlas) 13.5 KD 49 KD 23,7 KD The encoded protein(TYKY) contains two [4Fe-4S] ferredoxin consensus patterns [PMID: 9837812] b2c 20 kD 38.2 kDa seems to participate in the assembly of the Q-module necessary to maintain normal MT-ND1 synthesis fad Chaperone Remain bound to this module until the final assembly steps Chaperone Remain bound to this module until the final assembly steps e14 aka C3ORF1 Chaperone remains bound to the Q/ND1 subassembly until the last maturation steps. fe2 c23 9.3 KD 20 kD 17 kD 12 KD ~12 KD 16.4 KD 22 KD 22 KD ~16 KD 67 KD 12 KD ~12 KD 16.4 KD 22 KD 22 KD ~16 KD DMAC1/TMEM261 is implicated in the stabilization and/or assembly of the ND5-module 11,8 KD d45 18 KD 11 KD 8.1 KD 41KD 15KD Chaperone f38 e00 ca9 Chaperone f38 e00 ca9 Chaperone f38 Chaperone ca9 e00 Chaperone f38 Chaperone e00 ca9 dbe d51 da8 b41 d45 fe2 aka cV assembly factor e31 da8 f38 Chaperone f38 Chaperone e00 ca9 18 KD 11 KD 8.1 KD 41KD 15KD dbe d51 da8 b41 d45 fe2 aka cV assembly factor e31 da8 f38 Chaperone f38 Chaperone e00 ca9 30.2 KDa (protein atlas) 13.5 KD 49 KD 23,7 KD The encoded protein(TYKY) contains two [4Fe-4S] ferredoxin consensus patterns [PMID: 9837812] b2c 20 kD 38.2 kDa seems to participate in the assembly of the Q-module necessary to maintain normal MT-ND1 synthesis fad Chaperone Remain bound to this module until the final assembly steps Chaperone Remain bound to this module until the final assembly steps e14 aka C3ORF1 Chaperone remains bound to the Q/ND1 subassembly until the last maturation steps. fe2 c23 9.3 KD 20 kD 17 kD 18 KD 11 KD 8.1 KD 41KD 15KD dbe d51 da8 b41 d45 fe2 aka cV assembly factor e31 da8 f38 Chaperone f38 Chaperone e00 ca9 30.2 KDa (protein atlas) 13.5 KD 49 KD 23,7 KD The encoded protein(TYKY) contains two [4Fe-4S] ferredoxin consensus patterns [PMID: 9837812] b2c 20 kD 38.2 kDa seems to participate in the assembly of the Q-module necessary to maintain normal MT-ND1 synthesis fad Chaperone Remain bound to this module until the final assembly steps Chaperone Remain bound to this module until the final assembly steps e14 aka C3ORF1 Chaperone remains bound to the Q/ND1 subassembly until the last maturation steps. fe2 c23 9.3 KD 20 kD 17 kD 67 KD 12 KD ~12 KD 16.4 KD 22 KD 22 KD ~16 KD DMAC1/TMEM261 is implicated in the stabilization and/or assembly of the ND5-module 11,8 KD d45 Stabilising intermediated only lacking the N-module f32 cb9 d45 18 KD 11 KD 8.1 KD 41KD 15KD dbe d51 da8 b41 d45 fe2 aka cV assembly factor e31 da8 f38 Chaperone f38 Chaperone e00 ca9 30.2 KDa (protein atlas) 13.5 KD 49 KD 23,7 KD The encoded protein(TYKY) contains two [4Fe-4S] ferredoxin consensus patterns [PMID: 9837812] b2c 20 kD 38.2 kDa seems to participate in the assembly of the Q-module necessary to maintain normal MT-ND1 synthesis fad Chaperone Remain bound to this module until the final assembly steps Chaperone Remain bound to this module until the final assembly steps e14 aka C3ORF1 Chaperone remains bound to the Q/ND1 subassembly until the last maturation steps. fe2 c23 9.3 KD 20 kD 17 kD Not in Figure at first step, but written down in text! Methylated on Arg(85) Methylated on Arg(85) hydroxyl group added to Arg(73) fbf d45 Essentail modification for cI assembly ed5 d45 f38 d45 d45 f38 d45 cb9 f32 f38 b82 dbe b02 f38 NDUFAF7 dimethylates NDUFS2 in Arg(85) d03 NDUFAF5 adds a hydroxyl group to Arg73 of NDUFS7 e5d d45 f38 b82 dbe b02 NDUFAF3 and 4 remain bound to this module until the final assembly steps f38 This intermediate only lacking the N-module is stabilized by NDUFAF2/NDUFA12L/B17.2L This intermediate only lacking the N-module is stabilized by NDUFAF2/NDUFA12L/B17.2L Consists out of 45 subunits Encoded by mtDNA and nDNA L-shaped enzyme with hydrophilic arm for electron transfer, hydrophobic arm for proton translocation 14 subunits perform catalytic activity Hydrophilic arm consists out of 7 subunits, which contain redox active centres Hydrophobic arm consists out of 7 subunits, which form proton channels. 30 remaning subunits are crucial for assembly and stability. 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