PhaR, a protein of unknown function conserved among short-chain-length polyhydroxyalkanoic acids producing bacteria, is a DNA-binding protein and represses Paracoccus denitrificans phaP expression in vitro.
A putative regulatory protein, PhaR, which was identified in the polyhydroxyalkanoic acid synthetic locus (phaZCPR) in Paracoccus denitrificans, was investigated. The PhaR protein purified from a recombinant Escherichia coli was estimated to be 22 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, being consistent with the mass calculated from the nucleotide sequence. The molecular mass was determined to be 93 kDa by size-exclusion chromatography, suggesting that the protein formed a tetramer. A gel mobility shift assay showed that PhaR specifically bound to the intergenic region of phaC--phaP. In a cell-free protein synthesis system using E. coli S30 extract, the expression of the phaP gene was repressed by the addition of purified PhaR. These results suggest that PhaR is a DNA-binding protein and may play a role in the regulation of phaP gene expression.
Maehara
A
A
Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Japan.
Doi
Y
Y
Nishiyama
T
T
Takagi
Y
Y
Ueda
S
S
Nakano
H
H
Yamane
T
T
D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002474:Cell-Free System; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006880:Hydroxy Acids / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism; D008970:Molecular Weight; D010231:Paracoccus denitrificans / Q000235:genetics*; D011091:Polyesters / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014176:Protein Biosynthesis; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D000094122:Polyhydroxybutyrates
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D006880:Hydroxy Acids; D006885:Hydroxybutyrates; D011091:Polyesters; D011994:Recombinant Proteins; D012097:Repressor Proteins; C118828:PHAP protein, Bacteria; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates