Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-2-5
pubmed:abstractText
Thioredoxin, a redox active protein, has been previously demonstrated to be essential for growth of the anoxygenic photosynthetic bacterium Rhodobacter sphaeroides. In the present study, the involvement of thioredoxin in the formation of the photosynthetic apparatus of R. sphaeroides WS8 was investigated by construction and analysis of a mutant strain disrupted for the chromosomal trxA copy and carrying a plasmid-borne copy of trxA under the control of the hybrid ptrc promoter inducible by IPTG (isopropyl-beta-D-thiogalactopyranoside). This strain was viable in the absence of IPTG but was affected in pigmentation. When shifted from high to low oxygen tension conditions, the trxA mutant showed a reduced bacteriochlorophyll content in comparison to that of the wild type. Although thioredoxin is able to regulate aminolevulinic acid (ALA) synthase (the first enzyme of the tetrapyrrole biosynthetic pathway) activity by a dithiol-disulfide exchange, our mutant strain exhibited a level of ALA synthase activity identical to that of the wild type, suggesting that thioredoxin is involved in other steps to regulate the synthesis of the photosynthetic apparatus. Accordingly, we showed that the trxA mutation affects the oxygen-regulated expression of the puf operon encoding the pigment-binding proteins of the light-harvesting and reaction center complexes. Upon transition from aerobic to semiaerobic growth conditions, the maximal puf mRNA level was found to be 40 to 50% lower in the mutant strain than in the wild type. The stability of the puf transcripts was identical in both strains grown under low oxygen tension, indicating that the role of thioredoxin in regulating puf expression occurs at the transcriptional level.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-109312, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-1547494, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-1910303, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-232214, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-2492995, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-2853689, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-2970625, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-3027044, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-3889924, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-3896121, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-391270, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-407213, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-6237955, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-6363212, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-7583144, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-7642486, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-7683456, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-7751278, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-7768793, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-7883723, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-7992056, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8282708, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8468291, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8550440, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8580841, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8620537, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8628218, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8756494, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-8981989, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-9025281, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-9218481, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-942051, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-9515919, http://linkedlifedata.com/resource/pubmed/commentcorrection/9864318-9603864
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9193
pubmed:author
pubmed:issnType
Print
pubmed:volume
181
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
100-6
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed-meshheading:9864318-5-Aminolevulinate Synthetase, pubmed-meshheading:9864318-Bacterial Proteins, pubmed-meshheading:9864318-Bacteriochlorophylls, pubmed-meshheading:9864318-Base Sequence, pubmed-meshheading:9864318-DNA Primers, pubmed-meshheading:9864318-Gene Expression Regulation, Bacterial, pubmed-meshheading:9864318-Genes, Bacterial, pubmed-meshheading:9864318-Isopropyl Thiogalactoside, pubmed-meshheading:9864318-Light-Harvesting Protein Complexes, pubmed-meshheading:9864318-Mutation, pubmed-meshheading:9864318-Operon, pubmed-meshheading:9864318-Oxidation-Reduction, pubmed-meshheading:9864318-Oxygen, pubmed-meshheading:9864318-Phenotype, pubmed-meshheading:9864318-Photosynthesis, pubmed-meshheading:9864318-Photosynthetic Reaction Center Complex Proteins, pubmed-meshheading:9864318-Rhodobacter sphaeroides, pubmed-meshheading:9864318-Thioredoxins
pubmed:year
1999
pubmed:articleTitle
Thioredoxin is involved in oxygen-regulated formation of the photosynthetic apparatus of Rhodobacter sphaeroides.
pubmed:affiliation
Institut für Mikrobiologie und Molekularbiologie, D-35392 Giessen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't