Cisplatin-induced haemolytic uraemic syndrome associated with a novel intronic mutation of treated with eculizumab.

A 2-year-old patient with a neuroblastoma developed haemolytic uraemic syndrome (HUS) following treatment with cisplatin and carboplatin. Following treatment with eculizumab, there was a substantial improvement in renal function with the recovery of the platelet count and the cessation of haemolysis. Subsequent investigations showed a novel, heterozygous splice site mutation with reduced peripheral blood neutrophil CD46 expression.

A RecB-family nuclease motif in the Type I restriction endonuclease EcoR124I.

The Type I restriction-modification enzyme EcoR124I is an ATP-dependent endonuclease that uses dsDNA translocation to locate and cleave distant non-specific DNA sites. Bioinformatic analysis of the HsdR subunits of EcoR124I and related Type I enzymes showed that in addition to the principal PD-(E/D)xK Motifs, I, II and III, a QxxxY motif is also present that is characteristic of RecB-family nucleases. The QxxxY motif resides immediately C-terminal to Motif III within a region of predicted alpha-helix.

Direct and random routing of a molecular motor protein at a DNA junction.

With the aim of investigating how motor proteins negotiate DNA nanostructures, we produced test circuits based on recombination intermediates in which 1D translocation across a Holliday junction (HJ) could be assessed by subsequent triplex displacement signals on each DNA arm. Using the EcoR124I restriction-modification enzyme, a 3'-5' double-strand DNA (dsDNA) translocase, we could show that the motor will tend to follow its translocated strand across a junction. Nonetheless, as the frequency of junction bypass events increases, the motor will occasionally jump tracks.

When a helicase is not a helicase: dsDNA tracking by the motor protein EcoR124I.

Using a combination of single molecule and bulk solution measurements, we have examined the DNA translocation activity of a helicase, the Type I restriction modification enzyme EcoR124I. We find that EcoR124I can translocate past covalent interstrand crosslinks, inconsistent with an obligatory unwinding mechanism. Instead, translocation of the intact dsDNA occurs principally via contacts to the sugar-phosphate backbone and bases of the 3'-5' strand; contacts to the 5'-3' strand are not essential for motion but do play a key role in stabilising the motor on the DNA.

Characterisation of the Escherichia coli mfd promoter.

The bacterial mfd gene encodes a transcription-repair coupling factor that mediates the preferential repair of DNA damage in the template strand of active transcriptional units. In this report, the transcription start site for the Escherichia coli mfd gene was determined in vivo and in vitro, and the DNA determinants for mfd transcription by deletion and site-directed mutagenesis were defined. A canonical sigma(70)-dependent promoter, mfd P1, was responsible for the majority of mfd transcription, and a core region consisting of residues -42 to +5 was sufficient for full activity in rich and minimal media.