Fig 5.

13.4L interacts with complex I assembly intermediates. (A) Immunoprecipitation of complex I subunits with 13.4L antiserum. Immunoprecipitates were analyzed by Western blotting with a mixture of antisera against the proteins indicated on the left (subunits 30.4, 29.9, and 21.3c kDa belong to the Q module; subunits 20.8, 14, and 12.3 kDa are part of the P module). (B) Immunoprecipitation of the 13.4L protein by antiserum against complex I. Mitochondria from nuo21 (a) and nuo51 (b) were separately solubilized and incubated with either an antiserum to the whole complex I (1) or an antibody to the 13.4L protein (2). The immunoprecipitates were analyzed by Western blotting with a mixture of antisera against the proteins indicated on the left. (C and D) Association of the 13.4L to complex I assembly intermediates. Mitochondrial proteins were resolved by BN PAGE (4 to 13%) and subsequently analyzed by Western blotting with antisera against the 13.4L protein (C) and the 21.3c kDa subunit of complex I (D).