Colicin A immunity protein interacts with the hydrophobic helical hairpin of the colicin A channel domain in the Escherichia coli inner membrane.
The colicin A pore-forming domain (pfColA) was fused to a bacterial signal peptide (sp-pfColA). This was inserted into the Escherichia coli inner membrane in functional form and could be coimmunoprecipitated with epitope-tagged immunity protein (EpCai). We constructed a series of fusion proteins in which various numbers of sp-pfColA alpha-helices were fused to alkaline phosphatase (AP). We showed that a fusion protein made up of the hydrophobic alpha-helices 8 and 9 of sp-pfColA fused to AP was specifically coimmunoprecipitated with EpCai produced in the same cells. This is the first biochemical evidence that Cai recognizes and interacts with the colicin A hydrophobic helical hairpin.
Nardi
A
A
Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Biologie Structurale et Microbiologie, CNRS, Marseille, France.
Corda
Y
Y
Baty
D
D
Duché
D
D
D000469:Alkaline Phosphatase / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D003087:Colicins / Q000737:chemistry / Q000378:metabolism*; D000939:Epitopes / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D007425:Intracellular Membranes / Q000737:chemistry / Q000378:metabolism; D007473:Ion Channels / Q000737:chemistry / Q000378:metabolism*; D046911:Macromolecular Substances; D011233:Precipitin Tests; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000378:metabolism
D001426:Bacterial Proteins; D003087:Colicins; D000939:Epitopes; D007473:Ion Channels; D046911:Macromolecular Substances; D011993:Recombinant Fusion Proteins; C007104:colicin immunity proteins; D000469:Alkaline Phosphatase