Michèle Rossignol

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We have explored the Escherichia coli chromosome architecture by genetic dissection, using a site-specific recombination system that reveals the spatial proximity of distant DNA sites and records interactions. By analysing the percentages of recombination between pairs of sites scattered over the chromosome, we observed that DNA interactions were restricted(More)
The transcription/DNA repair factor TFIIH consists of nine subunits, several exhibiting known functions: helicase/ATPase, kinase activity and DNA binding. Three subunits of TFIIH, cdk7, cyclin H and MAT1, form a ternary complex, cdk-activating kinase (CAK), found either on its own or as part of TFIIH. In the present work, we demonstrate that purified human(More)
The filamentous fungus Podospora anserina presents a degeneration syndrome called Senescence associated with mitochondrial DNA modifications. We show that mutations affecting the two different and interacting cytosolic ribosomal proteins (S7 and S19) systematically and specifically prevent the accumulation of senDNA alpha (a circular double-stranded DNA(More)
MAT1, cyclin H and cdk7 are part of TFIIH, a class II transcription factor which possesses numerous subunits of which several have been shown to be involved in processes other than transcription. Two of them, XPD (ERCC2) and XPB (ERCC3), are helicases involved in nucleotide excision repair (NER), whereas cdk7, cyclin H and MAT1 are thought to participate in(More)
The largest subunit of the human basal transcription factor TFIIFalpha (also called RAP74) was reported previously to be the target of some phospho/dephosphorylation process. We show that TFIIFalpha possesses a serine/threonine kinase activity, allowing an autophosphorylation of the two residues at position serine 385 and threonine 389. Mutation analysis(More)
We have constructed an R6K-based suicide vector that permits the random insertion of a mini-transposon named NKBOR into the chromosome of Gram-negative bacteria and the subsequent rapid cloning of sequences flanking the insertion site in Escherichia coli. This mini-transposon contains a conditional R6K plasmid origin of replication, a kanamycin resistance(More)
The mitochondrial chromosome of 15 Podo-spora anserina and one Podospora comata wild-type strains have been extensively examined for the presence of optional elements and for sequence divergence. Among the P. anserina strains, nine optional sequences were found. By comparing P. anserina with the closely related and weakly interfertile P. comata species, six(More)
Some mutant strains of the filamentous fungus Podospora anserina spontaneously present a growth impairment, which has been called Crippled Growth (CG). CG is caused by a cytoplasmic and infectious factor, C. C is efficiently transmitted during mitosis but is not transmitted to the progeny after sexual crosses. C is induced by stationary phase and cured by(More)
We have cloned and sequenced the gene encoding the translation elongation factor eEF1A from two filamentous fungi, Podospora curvicolla and Sordaria macrospora. These fungi are close relatives of Podospora anserina and also show senescence syndromes. Comparison of the sequences of the deduced proteins with that of P. anserina reveals that the three proteins(More)
The mitochondrial genome of 23 wild-type strains belonging to three different species of the filamentous fungus Podospora was examined. Among the 15 optional sequences identified are two intronic reading frames, nad1-i4-orf1 and cox1-i7-orf2. We show that the presence of these sequences was strictly correlated with tightly clustered nucleotide substitutions(More)