EC Number   |
General Information |
Reference |
|---|
   5.6.2.4 | evolution |
conserved helicase domains of EcUvrB and MtUvrB |
-, 756042 |
| 5.6.2.4 | evolution |
superfamilies 1 and 2 (SF1 and SF2) comprise the largest number of helicase families and members are involved in a wide array of cellular functions that require manipulation of DNA or RNA structures, the helicases belong to the AAA+ ATPases. Helicase superfamilies can also be subdivided into those that translocate along DNA and unwind in a 3'-5' direction, e.g., SF1A, or a 5'-3 direction, e.g., SF1B. SF1 and SF2 helicases can be identified based on evolutionary conservation of seven sequence motifs (I, Ia, II-VI) that are required for ATP binding/hydrolysis, nucleic acid binding, and/or translocation. SF1 and SF2 helicases include a conserved core helicase domain that is comprised of two subdomains that share similarity with RecA ATPase/recombinase enzyme family |
-, 735221 |
| 5.6.2.4 | evolution |
the enzyme belongs to the RecQ protein family, a group of helicases highly conserved from bacteria to humans and playing a critical role in transcription, DNA replication, DNA recombination, and DNA repair |
756684 |
| 5.6.2.4 | evolution |
the enzyme demonstrates a unique capacity of a viral helicase having evolved to stimulate a cellular replicative DNA polymerase |
757848 |
| 5.6.2.4 | malfunction |
enzyme gene mutations lead to Bloom's syndrome, an autosomal recessive condition characterized by short stature, immunodeficiency, and a greatly elevated frequency of many types of cancer |
763230 |
| 5.6.2.4 | malfunction |
gene RECQL4 mutations are associated with Rothmund Thomson syndrome (RTS), RAPADILINO syndrome and Baller-Gerold syndrome. These patients display a range of benign skeletal abnormalities such as low bone mass. In addition, RTS patients have a highly increased incidence of osteosarcoma (OS). Mechanism for the benign skeletal phenotypes of RECQL4 mutation syndromes, overview |
758107 |
| 5.6.2.4 | malfunction |
genetic disruption of the enzyme human cells enhances cellular sensitivity and chromosome radial formation by the interstrand crosslink-inducing agent mitomycin C |
763506 |
| 5.6.2.4 | malfunction |
homozygous null mutants do not survive past the first instar because of severe defects in replication |
763243 |
| 5.6.2.4 | malfunction |
loss of RECQ4A leads to elevated homologous recombination frequencies and hypersensitivity to genotoxic agents. Loss of helicase activity or deletion of the N-terminus only partially complemented the mutant hyper-recombination phenotype. The helicase-deficient protein lacking its N-terminus does not complement the hyper-recombination phenotype at all. The recq4A-4 mutant is hypersensitive to treatment with cisplatin. The loss of RECQ4A also leads to a hypersensitivity to the DNA methylating agent MMS. Deletion of the RECQ4A N-terminus does not affect the viability of plants but results in a DNA repair defect |
734799 |
| 5.6.2.4 | malfunction |
mechanism for the benign skeletal phenotypes of RECQL4 mutation syndromes, overview. Recql4 deletion in vivo at the osteoblastic progenitor stage of differentiation results in mice with shorter bones and reduced bone volume, assessed at 9 weeks of age. This is associated with an osteoblast intrinsic decrease in mineral apposition rate and bone formation rate in the Recql4-deficient cohorts. Deletion of Recql4 in mature osteoblasts/osteocytes in vivo, does not cause a detectable phenotype. Acute deletion of Recql4 in primary osteoblasts or shRNA knockdown in an osteoblastic cell line cause failed proliferation, accompanied by cell cycle arrest, induction of apoptosis and impaired differentiation. Tumor suppression and osteosarcoma susceptibility are most likely a function of mutant, not null, alleles of RECQL4. Reduced skeletal growth in Osx-Cre Recql4fl/fl mice. The concurrent loss of p53 does not rescue Recql4 deficient osteoblast proliferation |
758107 |
