Cloning and characterization of a gene, mpsA, encoding a protein associated with intracellular magnetic particles from Magnetospirillum sp. strain AMB-1.
Proteins located within the lipid bilayer, surrounding the intracellular bacterial magnetic particles (BMP) from Magnetospirillum sp. AMB-1, were separated using SDS-PAGE. Several major proteins of approximate molecular weight 66.2, 35.6, and 24.8 kDa were identified. The N-terminal amino acid sequence of one of these proteins, designated MpsA, was determined and used to design a pair of PCR primers which amplified a 105 bp DNA fragment from AMB-1 genomic DNA. Gene-walking, using anchored PCR, was used to determine the complete nucleotide sequence (954 bp) of the mpsA gene. The mpsA encodes a 317 amino acid protein which does not have an N-terminal cytoplasmic transport signal sequence. Intracellular localization studies were carried out using an mpsA-luc gene fusion expressed in AMB-1 following gene transfer by conjugation. The gene fusion was constructed by cloning a 1.6 kb mpsA fragment upstream of luc in the conjugal plasmid pKLC. The MpsA-Luc fusion protein was preferentially located on the magnetic particle membrane. Although the function of MpsA remains unknown, homology searches suggest similarity with the alpha subunit of acetyl-CoA carboxylase and the CoA-binding motif.
Matsunaga
T
T
Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16 Koganei, Tokyo, 184-8588, Japan. tmatsuna@cc.tuat.ac.jp
Tsujimura
N
N
Okamura
Y
Y
Takeyama
H
H
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D008280:Magnetics; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012244:Rhodospirillaceae / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D008565:Membrane Proteins; C405425:MpsA protein, Magnetospirillum sp.