title: Disrupting the Acyl Carrier Protein/SpoT interaction in vivo: identification of ACP residues involved in the interaction and consequence on growth.
abstract: In bacteria, Acyl Carrier Protein (ACP) is the central cofactor for fatty acid biosynthesis. It carries the acyl chain in elongation and must therefore interact successively with all the enzymes of this pathway. Yet, ACP also interacts with proteins of diverse unrelated function. Among them, the interaction with SpoT has been proposed to be involved in regulating ppGpp levels in the cell in response to fatty acid synthesis inhibition. In order to better understand this mechanism, we screened for ACP mutants unable to interact with SpoT in vivo by bacterial two-hybrid, but still functional for fatty acid synthesis. The position of the selected mutations indicated that the helix II of ACP is responsible for the interaction with SpoT. This suggested a mechanism of recognition similar to one used for the enzymes of fatty acid synthesis. Consistently, the interactions tested by bacterial two-hybrid of ACP with fatty acid synthesis enzymes were also affected by the mutations that prevented the interaction with SpoT. Yet, interestingly, the corresponding mutant strains were viable, and the phenotypes of one mutant suggested a defect in growth regulation.
authors.affiliation: Laboratory of Macromolecular System Engineering (LISM), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille University, Marseille, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Angelini
authors.forename: Laetitia
authors.initials: L
authors.lastname: My
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Bouveret
mesh_terms: D000213:Acyl Carrier Protein / Q000737:chemistry / Q000378:metabolism*; D000215:Acylation; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D001681:Biological Assay; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D054889:Fatty Acid Synthase, Type II / Q000737:chemistry / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011485:Protein Binding; D011755:Pyrophosphatases / Q000378:metabolism*; D015203:Reproducibility of Results; D020798:Two-Hybrid System Techniques
chemical_list: D000213:Acyl Carrier Protein; D000596:Amino Acids; D029968:Escherichia coli Proteins; D005227:Fatty Acids; D050505:Mutant Proteins; C040157:acpP protein, E coli; C027627:guanosine-3',5'-bis(diphosphate) 3'-pyrophosphatase; D011755:Pyrophosphatases; D054889:Fatty Acid Synthase, Type II