A Novel Phosphopantetheine:Protein Transferase Activating Yeast Mitochondrial Acyl Carrier Protein

• Published in: The Journal of biological chemistry 1998-08, Vol.273 (35), p.22334-22339
• Main Authors: Stuible, Hans-Peter, Meier, Sandra, Wagner, Christian, Hannappel, Ewald, Schweizer, Eckhart
• Format: Article
• Language: English
• Subjects: ACIDE LIPOIQUE; ACIDO LIPOICO; ACP protein; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Acyl Carrier Protein - metabolism; Amino Acid Sequence; AMINO ACID SEQUENCES; Base Sequence; BINDING PROTEINS; Brevibacterium ammoniagenes; CHEMICAL COMPOSITION; CHEMICAL REACTIONS; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; DNA Primers; ENZYMIC ACTIVITY; fatty-acid synthase; FENOTIPOS; GENBANK/Y16253; GENE; GENES; LIPOGENESE; LIPOGENESIS; LIPOIC ACID; MITOCHONDRIA; Mitochondria - metabolism; MITOCHONDRIE; MITOCONDRIA; MOLECULAR SEQUENCE DATA; Mutagenesis, Site-Directed; MUTANT; MUTANTES; MUTANTS; NUCLEOTIDE SEQUENCE; PHENOTYPE; PHENOTYPES; PHOSPHOPANTETHEINYLATION; phosphopanthetheine-protein transferase; Ppt1 protein; PPT2 GENE; PROTEINAS AGLUTINANTES; PROTEINE DE LIAISON; REACCIONES QUIMICAS; REACTION CHIMIQUE; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - metabolism; SECUENCIA NUCLEOTIDICA; Sequence Homology, Amino Acid; SEQUENCE NUCLEOTIDIQUE; STRUCTURAL GENES; THIOCTIC ACID; TRANSFERASAS; TRANSFERASE; TRANSFERASES; Transferases (Other Substituted Phosphate Groups) - chemistry; Transferases (Other Substituted Phosphate Groups) - genetics; Transferases (Other Substituted Phosphate Groups) - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.273.35.22334

In Saccharomyces cerevisiae, the low molecular weight acyl carrier protein (ACP) of mitochondrial type II fatty acid synthase (FAS) and the cytoplasmic type I FAS multienzyme contain 4′-phosphopantetheine as a prosthetic group. Sequence alignment studies with the recently isolated phosphopantetheine:protein transferase (PPTase), Ppt1p, from Brevibacterium ammoniagenes revealed the yeast open reading frame, YPL148C, as a potential PPTase gene (25% identical and 43% conserved amino acids). In accordance with this similarity, pantetheinylation of mitochondrial ACP was lost upon disruption of YPL148C. In contrast, biosynthesis of cytoplasmic holo-FAS remained unaffected by this mutation. According to these characteristics, the newly identified gene was designated asPPT2. Similar to ACP null mutants, cellular lipoic acid synthesis and, hence, respiration were abolished in PPT2deletants. ACP pantetheinylation, lipoic acid synthesis, and respiratory competence were restored upon transformation ofPPT2 mutants with cloned PPT2 DNA. In vitro, holo-ACP synthesis was achieved by incubating apo-ACP with coenzyme A in the presence of purified Ppt2p. The homologous yeast enzyme could be replaced, in this assay, by the ACP synthase (EC2.7.8.7) of Escherichia coli but not by the type I FAS-specific PPTase of B. ammoniagenes, Ppt1p. These results conform with the inability of Ppt2p to activate the cytoplasmic type I FAS complex of yeast.