Several eukaryotic homologs of the Escherichia coli RecQ DNA helicase have been found. These include the human BLM gene, whose mutation results in Bloom syndrome, and the human WRN gene, whose mutation leads to Werner syndrome resembling premature aging. We cloned a Drosophila melanogaster homolog of the RECQ helicase family, Dmblm (Drosophila melanogaster Bloom), which encodes a putative 1487-...

Bloom syndrome and Werner syndrome are genetic disorders in which an increased rate of chromosomal abnormality is observed. The genes responsible for these diseases, BLM and WRN, have been cloned and identified as homologs of the Escherichia coli recQ genes. We studied the effect of recQ mutations on illegitimate recombination, which is an aberrant biological event related to the chromosomal ab...

RecQ helicases feature multiple domains in their structure, of which the helicase domain, the RecQ-Ct domain and the HRDC domains are well conserved among the SF2 helicases. The helicase domain and the RecQ-Ct domain constitute the catalytic core of the enzyme. The domain interfaces are the DNA binding sites which display significant conformational changes in our molecular dynamics simulation s...

RecQ helicases unwind remarkably diverse DNA structures as key components of many cellular processes. How RecQ enzymes accommodate different substrates in a unified mechanism that couples ATP hydrolysis to DNA unwinding is unknown. Here, the X-ray crystal structure of the Cronobacter sakazakii RecQ catalytic core domain bound to duplex DNA with a 3' single-stranded extension identifies two DNA-...

E. coli RecQ protein is a multifunctional helicase with homologs that include the S. cerevisiae Sgs1 helicase and the H. sapiens Wrn and Blm helicases. Here we show that RecQ helicase unwinds a covalently closed double-stranded DNA (dsDNA) substrate and that this activity specifically stimulates E. coli topoisomerase III (Topo III) to fully catenate dsDNA molecules. We propose that these protei...

The RecQ helicases represent a subfamily of DNA helicases that are highly conserved in evolution. Loss of RecQ helicase function leads to a breakdown in the maintenance of genome integrity, in particular hyper-recombination. Germ-line defects in three of the five known human RecQ helicases give rise to defined genetic disorders associated with cancer predisposition and/or premature aging. These...

The RecQ family of DNA helicases is highly conserved in evolution from bacteria to mammals. There are five human RecQ family members (RECQ1, BLM, WRN, RECQ4 and RECQ5), defects, three of which give rise to inherited human disorders. Mutations of BLM have been identified in patients with Bloom's syndrome, WRN has been shown to be mutated in Werner's syndrome, while mutations of RECQ4 have been a...

Members of the RecQ family of DNA helicases are involved in processes linked to DNA replication, DNA recombination and gene silencing. RecQ homologues of various animals have been described recently. Here, for the first time for plants, we characterised cDNAs of all in all six different RecQ-like proteins that are expressed to different extents in Arabidopsis thaliana. Surprisingly, three of th...

The RecQ helicases constitute a small but highly conserved helicase family. Proteins in this family are of particular interest because they are critical to maintenance of genomic stability in prokaryotes and eukaryotes. Eukaryotic RecQ helicase family members have been shown to unwind not only DNA duplexes but also DNAs with alternative structures, including structures stabilized by G quartets ...

RecQ5 is one of five RecQ helicase homologs identified in humans. Three of the human RecQ homologs (BLM, WRN and RTS) have been linked to autosomal recessive human genetic disorders (Bloom syndrome, Werner syndrome and Rothmund-Thomson syndrome, respectively) that display increased genomic instability and cause elevated levels of cancers in addition to other symptoms. To understand the role of ...