Disease relevance of Hlc

• The C-terminal region contains the canonical DNA polymerase motifs A, B, and C found in the family A type of DNA polymerases, which includes Escherichia coli polymerase I. The N-terminal region contains a putative ATP binding domain but not motifs for a helicase [1].
• One ORF encodes a picornavirus-like cassette of proteins for virus replication, including an iflavirus-like RNA-dependent RNA polymerase and a helicase that is related to those of mammalian picornaviruses [2].
• The deduced amino acid sequence of the 5' ORF1 (nucleotides 605 to 6325) showed significant similarity to the RNA-dependent RNA polymerase, helicase, and protease domains of viruses from the picornavirus, comovirus, calicivirus, and sequivirus families, as well as to a novel group of insect-infecting RNA viruses [3].
• A putative DNA helicase and novel oligoribonuclease in the Diachasmimorpha longicaudata entomopoxvirus (DlEPV) [4].
• The DlEPV helicase is also distinct from that of the Diadromus pulchellus ascovirus 1a from the D. pulchellus parasitic wasp, with less than 10% amino acid identity [4].

High impact information on Hlc

• SDE3 encodes an RNA helicase required for post-transcriptional gene silencing in Arabidopsis [5].
• Its deduced amino acid sequence contains short motifs which place it in a large superfamily of proteins of known or putative helicase activity [6].
• Arabidopsis TEBICHI, with helicase and DNA polymerase domains, is required for regulated cell division and differentiation in meristems [7].
• Isolation of the Cdc45/Mcm2-7/GINS (CMG) complex, a candidate for the eukaryotic DNA replication fork helicase [8].
• ATRX is a member of the SNF2 family of helicase/ATPases that is thought to regulate gene expression via an effect on chromatin structure and/or function [9].

Biological context of Hlc

• Overexpression of helicase active site mutants K388A and D483A results in a severe depletion of mtDNA and a dominant negative lethal phenotype [10].
• This kinase is crucial in transcriptional activation, V(D)J recombination, double-strand break repair, and both topoisomerase and helicase activities [11].
• The haywire gene of Drosophila encodes a putative helicase essential for transcription and nucleotide excision repair [12].
• The deduced amino acid sequence of the first open reading frame (nucleotides 571 to 6003) contained conserved sequence motifs for picornavirus RNA helicase, cysteine protease, and RNA-dependent RNA polymerase [13].
• The largest gene (RI-35-3) is under the control of an intermediate/late promoter and is presumed to encode a cytoplasmic 480 aa DNA-dependent DNA helicase with conserved motifs that are characteristic of DExH helicases [4].

Anatomical context of Hlc

• An3 mRNA encodes an RNA helicase that colocalizes with nucleoli in Xenopus oocytes in a stage-specific manner [14].
• The DEAD-box RNA helicase Vasa (Vas) is required for germ cell development and function, as well as for embryonic somatic posterior patterning [15].
• We have examined whether DNA strand exchange activities from nuclear extracts of HeLa cells or Drosophila melanogaster embryos have detectable helicase or melting activities [16].
• Our dominant negative analysis of d-mtDNA helicase in cultured cells provides a tractable model for understanding human autosomal dominant progressive external ophthalmoplegia mutations [10].
• Cloning, expression and localization of an RNA helicase gene from a human lymphoid cell line with chromosomal breakpoint 11q23.3 [17].

Associations of Hlc with chemical compounds

• This new helicase differs from all others known by having glycine-rich repeats at both the amino and carboxyl termini [18].

Other interactions of Hlc

• A Drosophila RNA helicase gene, pitchoune, is required for cell growth and proliferation and is a potential target of d-Myc [19].

Analytical, diagnostic and therapeutic context of Hlc

• Crystallization and preliminary X-ray analysis of the helicase domains of Vasa complexed with RNA and an ATP analogue [20].

References