title: The acidic, glutamine-rich Mpn474 protein of Mycoplasma pneumoniae is surface exposed and covers the complete cell.
abstract: The protein Mpn474 encoded by the mpn474 gene of the human-pathogenic Mycoplasma pneumoniae contains 1033 amino acids and has an isoelectric point of 4.79, which is caused by the large excess of glutamic acid residues (11 %). Although the protein lacks recognizable export signals we showed by immuno-electron microscopy that Mpn474 is surface exposed, covering the cell completely. By combining cross-linking and careful treatment of the bacterial cells with Triton X-100, we found that this protein is weakly bound to the cell surface, while the true transmembrane protein Mpn141 (adhesin P1) is firmly attached under the same experimental conditions. A transposon mutant in the mpn474 gene, which has no obvious phenotype, served as negative control for the immunodetection.
authors: Abteilung für Allgemeine Mikrobiologie, Institut für Mikrobiologie und Genetik, Grisebachstr. 8, D-37077 Göttingen, Germany.
authors: Jan
authors: J
authors: Hegermann
authors: Abteilung für Allgemeine Mikrobiologie, Institut für Mikrobiologie und Genetik, Grisebachstr. 8, D-37077 Göttingen, Germany.
authors: Sven
authors: S
authors: Halbedel
authors: Institut für Medizinische Mikrobiologie und Hygiene, Technische Universität, Medizinische Fakultät Carl Gustav Carus, Fetscherstr. 74, D-01307 Dresden, Germany.
authors: Roger
authors: R
authors: Dumke
authors: Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany.
authors: Jörg
authors: J
authors: Regula
authors: Molecular and Cellular Modeling Group, EML Research, Schloss-Wolfsbrunnenweg 33, D-69118 Heidelberg, Germany.
authors: Razif R
authors: RR
authors: Gabdoulline
authors: Abteilung für Allgemeine Mikrobiologie, Institut für Mikrobiologie und Genetik, Grisebachstr. 8, D-37077 Göttingen, Germany.
authors: Frank
authors: F
authors: Mayer
authors: Abteilung für Allgemeine Mikrobiologie, Institut für Mikrobiologie und Genetik, Grisebachstr. 8, D-37077 Göttingen, Germany.
authors: Jörg
authors: J
authors: Stülke
authors: Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany.
authors: Richard
authors: R
authors: Herrmann
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D015153:Blotting, Western; D004251:DNA Transposable Elements; D017353:Gene Deletion; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics; D016253:Microscopy, Immunoelectron; D016254:Mutagenesis, Insertional; D009177:Mycoplasma pneumoniae / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D008565:Membrane Proteins