title: Synthesis of the apoprotein of cytochrome b in heme-deficient yeast cells.
abstract: The presence of the apoprotein of cytochrome b has been demonstrated in a mutant of Sacchromyces cerevisiae lacking delta-aminolevulinic acid synthase and, hence, devoid of heme. The apoprotein of cytochrome b present in the mutant was identical with cytochrome b of control cells (mutant cells grown in the presence of delta-aminolevulinic acid) by the following criteria: similar apparent molecular weights in dodecyl sulfate-polyacrylamide gel electrophoresis; anomalous migration behavior during electrophoresis in polyacrylamide gels of different porosities; identical gel pattern obtained after immunoprecipitation with specific antiserum against cytochrome b; and identical fingerprints obtained after limited proteolysis with Staphylococcus aureus V8 protease. The kinetics of incorporation in vivo of [35S]methionine into apoprotein of cytochrome b in the mutant suggested that heme deficiency may affect assembly into the membrane of subunits of the cytochrome b.c1 complex rather than synthesis of cytochrome b.
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000172:deficiency; D001059:Apoproteins / Q000096:biosynthesis*; D003513:Cycloheximide / Q000494:pharmacology; D003580:Cytochromes / Q000096:biosynthesis*; D006418:Heme / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D010446:Peptide Fragments / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*; D013367:Submitochondrial Particles / Q000378:metabolism
chemical_list: D001059:Apoproteins; D003580:Cytochromes; D010446:Peptide Fragments; D006418:Heme; D003513:Cycloheximide; D008715:Methionine; D000624:5-Aminolevulinate Synthetase