title: Identification of Escherichia coli proteins cross-reacting with antibodies against region 2.2 peptide of RNA polymerase sigma subunit.
abstract: Antisera against a synthetic tetradecameric peptide with the sequence DLIQEGNIGLMKAV, which is present in region 2.2 of both sigma 70 and sigma 32 subunits of Escherichia coli RNA polymerase, cross-reacted with more than 10 E. coli proteins including these two sigma subunits. Four major species of these cross-reacting proteins (SCRPs) were purified. N-Terminal amino acid sequence analysis revealed that one of them (SCRP-27A) was an as yet unidentified protein while the other three (SCRP-34, SCRP-27B and SCRP-23) were thioredoxin reductase, ribosomal protein S2, and alkyl hydroperoxide reductase, respectively. Immunological competition experiments with various fragments of this sigma region 2.2 peptide indicated that the anti-sigma peptide serum contained at least three different species of antibodies. All the four SCRPs analyzed here reacted with an antibody against a C-terminus-proximal epitope.
authors.affiliation: Department of Molecular Genetics, National Institute of Genetics, Shizuoka, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Ueshima
authors.forename: N
authors.initials: N
authors.lastname: Fujita
authors.forename: A
authors.initials: A
authors.lastname: Ishihama
mesh_terms: D000595:Amino Acid Sequence; D000906:Antibodies; D001426:Bacterial Proteins / Q000032:analysis* / Q000276:immunology; D015153:Blotting, Western; D003429:Cross Reactions; D012321:DNA-Directed RNA Polymerases / Q000032:analysis* / Q000276:immunology; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis; D012689:Sequence Homology, Nucleic Acid
chemical_list: D000906:Antibodies; D001426:Bacterial Proteins; D046911:Macromolecular Substances; D009842:Oligopeptides; D012321:DNA-Directed RNA Polymerases