title: Isolation of a periplasmic molecular chaperone-like protein of Rhodobacter sphaeroides f. sp. denitrificans that is homologous to the dipeptide transport protein DppA of Escherichia coli.
abstract: A periplasmic protein has been found to prevent aggregation of the acid-unfolded dimethyl sulfoxide reductase (DMSOR), the periplasmic terminal reductase of dimethyl sulfoxide respiration in the phototroph Rhodobacter sphaeroides f. sp. denitrificans, in a manner similar to that of the Escherichia coli chaperonin GroEL (Matsuzaki et al., Plant Cell Physiol. 37:333-339, 1996). The protein was isolated from the periplasm of the phototroph. It had a molecular mass of 58 kDa and had no subunits. The sequence of 14 amino-terminal residues of the protein was completely identical to that of the periplasmic dipeptide transport protein (DppA) of E. coli. The 58-kDa protein prevented aggregation to a degree comparable to that of GroEL on the basis of monomer protein. The 58-kDa protein also decreased aggregation of guanidine hydrochloride-denatured rhodanese, a mitochondrial matrix protein, during its refolding upon dilution. The 58-kDa protein is a kind of molecular chaperone and could be involved in maintaining unfolded DMSOR, after secretion of the latter into the periplasm, in a competent form for its correct folding.
authors.affiliation: Department of Biological Science, Faculty of Science, Hiroshima University, Higashi-Hiroshima 739, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsuzaki
authors.forename: Y
authors.initials: Y
authors.lastname: Kiso
authors.forename: I
authors.initials: I
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Satoh
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D002352:Carrier Proteins; D004926:Escherichia coli / Q000737:chemistry; D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; D018832:Molecular Chaperones / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry; D033902:Periplasmic Binding Proteins; D012242:Rhodobacter sphaeroides / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013884:Thiosulfate Sulfurtransferase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; D018832:Molecular Chaperones; D033902:Periplasmic Binding Proteins; C066768:dppA protein, E coli; D010088:Oxidoreductases; C045664:dimethyl sulfoxide reductase; D013884:Thiosulfate Sulfurtransferase