A novel peroxiredoxin of the plant Sedum lineare is a homologue of Escherichia coli bacterioferritin co-migratory protein (Bcp).
We cloned a gene encoding a 17-kDa protein from a cDNA library of the plant Sedum lineare and found that its deduced amino acid sequence showed similarities to those of Escherichia coli bacterioferritin co-migratory protein (Bcp) and its homologues, which comprise a discrete group associated with the peroxiredoxin (Prx) family. Studies of the recombinant 17-kDa protein produced in E. coli cells revealed that it actually had a thioredoxin-dependent peroxidase activity, the hallmark of the Prx family. PrxQ, as we now designate the 17-kDa protein, had two cysteine residues (Cys-44 and Cys-49) well conserved among proteins of the Bcp group. These two cysteines were demonstrated to be essential for the thioredoxin-dependent peroxidase activity by analysis of mutant proteins, suggesting that these residues are involved in the formation of an intramolecular disulphide bond as an intermediate in the reaction cycle. Expression of PrxQ suppressed the hypersensitivity of an E. coli bcp mutant to peroxides, indicating that it might exert an antioxidant activity in vivo.
Kong
W
W
Department of Microbiology, Faculty of Dentistry, Kyushu University, Fukuoka 812-8582, Japan.
Shiota
S
S
Shi
Y
Y
Nakayama
H
H
Nakayama
K
K
D000595:Amino Acid Sequence; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D019281:Dimerization; D004220:Disulfides / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D019684:Magnoliopsida / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation / Q000235:genetics; D010544:Peroxidases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010545:Peroxides / Q000378:metabolism / Q000494:pharmacology; D054464:Peroxiredoxins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013267:Stilbenes / Q000378:metabolism; D013451:Sulfonic Acids / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism
D000975:Antioxidants; D001426:Bacterial Proteins; D004220:Disulfides; D010545:Peroxides; D013267:Stilbenes; D013451:Sulfonic Acids; C079532:4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid; C068491:bacterioferritin comigratory protein, Bacteria; D013879:Thioredoxins; D010544:Peroxidases; D054464:Peroxiredoxins; D003545:Cysteine