Histidine 129 in the 75-kDa subunit of mitochondrial complex I from Yarrowia lipolytica is not a ligand for [Fe4S4] cluster N5 but is required for catalytic activity.
Respiratory chain complex I contains 8-9 iron-sulfur clusters. In several cases, the assignment of these clusters to subunits and binding motifs is still ambiguous. To test the proposed ligation of the tetranuclear iron-sulfur cluster N5 of respiratory chain complex I, we replaced the conserved histidine 129 in the 75-kDa subunit from Yarrowia lipolytica with alanine. In the mutant strain, reduced amounts of fully assembled but destabilized complex I could be detected. Deamino-NADH: ubiquinone oxidoreductase activity was abolished completely by the mutation. However, EPR spectroscopic analysis of mutant complex I exhibited an unchanged cluster N5 signal, excluding histidine 129 as a cluster N5 ligand.
Waletko
Antje
A
Universität Frankfurt, Fachbereich Medizin, Institut für Biochemie I, F-60590 Frankfurt am Main, Germany.
Zwicker
Klaus
K
Abdrakhmanova
Albina
A
Zickermann
Volker
V
Brandt
Ulrich
U
Kerscher
Stefan
S
D000595:Amino Acid Sequence; D002384:Catalysis; D004578:Electron Spin Resonance Spectroscopy; D042967:Electron Transport Complex I / Q000737:chemistry* / Q000378:metabolism*; D006639:Histidine / Q000235:genetics / Q000378:metabolism*; D006864:Hydrogenase / Q000737:chemistry / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion / Q000235:genetics; D025062:Yarrowia / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D007506:Iron-Sulfur Proteins; D008024:Ligands; D021122:Protein Subunits; D009243:NAD; D006639:Histidine; D006864:Hydrogenase; D042967:Electron Transport Complex I