title: Analysis of the PHA granule-associated proteins GA20 and GA11 in Methylobacterium extorquens and Methylobacterium rhodesianum.
abstract: Electrophoretic analysis of the proteins bound to poly(3-hydroxybutyric acid), PHB-, granules in Methylobacterium extorquens, M. rhodesianum as well as the PHB-leaky mutants Mu 1 and Mu 11, which were isolated from the latter, resulted in two dominant low-molecular weight proteins, which were referred to as GA11 and GA20. After purification of these proteins antibodies against the GA11 and GA20 protein of M. extorquens were obtained. Both proteins bound to the surface of PHB granules as revealed by immunoelectron microscopy of whole cells of M. extorquens and M. rhodesianum. With cells of the PHB-leaky mutants Mu 1 and Mu 11 no specific labeling was observed. The N-terminal amino acid sequences of the GA11 and the GA20 protein were determined. We found significant homologies between the sequences of the investigated strains. The use of oligonucleotide probes based on the N-terminal sequences of the GA20 protein from M. rhodesianum to identify the corresponding structural genes in various genomic libraries failed.
authors.affiliation: Universität Leipzig, Fakultät für Biowissenschaften, Pharmazie und Psychologie, Abteilung Biotechnologie, Leipzig, Germany.
authors.forename: C G
authors.initials: CG
authors.lastname: Föllner
authors.forename: M
authors.initials: M
authors.lastname: Madkour
authors.forename: F
authors.initials: F
authors.lastname: Mayer
authors.forename: W
authors.initials: W
authors.lastname: Babel
authors.forename: A
authors.initials: A
authors.lastname: Steinbüchel
mesh_terms: D000102:Acetyl-CoA C-Acyltransferase / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification*; D015153:Blotting, Western; D003001:Cloning, Molecular; D015342:DNA Probes / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D015723:Gene Library; D006088:Gram-Negative Aerobic Bacteria / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D006885:Hydroxybutyrates / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D017386:Sequence Homology, Amino Acid
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D015342:DNA Probes; D004269:DNA, Bacterial; D006885:Hydroxybutyrates; D000429:Alcohol Oxidoreductases; C023744:acetoacetyl-CoA reductase; D000102:Acetyl-CoA C-Acyltransferase