title: The first gene in the Escherichia coli secA operon, gene X, encodes a nonessential secretory protein.
abstract: TnphoA insertions in the first gene of the Escherichia coli secA operon, gene X, were isolated and analyzed. Studies of the Gene X-PhoA fusion proteins showed that gene X encodes a secretory protein, since the fusion proteins possessed normal alkaline phosphatase activity and a substantial portion of this activity was found in the periplasm. In addition, the Gene X-PhoA fusion proteins were initially synthesized with a cleavable signal peptide. A gene X::TnphoA insertion was used to construct a strain containing a disrupted chromosomal copy of gene X. Analysis of this strain indicated that gene X is nonessential for cell growth and viability and does not appear to play an essential role in the process of protein export.
authors.affiliation: Department of Microbiology, State University of New York, Stony Brook 11794-8626.
authors.forename: T
authors.initials: T
authors.lastname: Rajapandi
authors.forename: K M
authors.initials: KM
authors.lastname: Dolan
authors.forename: D B
authors.initials: DB
authors.lastname: Oliver
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009838:Oligodeoxyribonucleotides; D009876:Operon; D021382:Protein Sorting Signals / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D009838:Oligodeoxyribonucleotides; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins