title: Multiple ISWI ATPase complexes from xenopus laevis. Functional conservation of an ACF/CHRAC homolog.
abstract: The nucleosomal ATPase ISWI is the catalytic subunit of several protein complexes that either organize or perturb chromatin structure in vitro. This work reports the cloning and biochemical characterization of a Xenopus ISWI homolog. Surprisingly, whereas we find four complex forms of ISWI in egg extracts, we find no functional homolog of NURF. One of these complexes, xACF, consists of ISWI, Acf1, and a previously uncharacterized protein of 175 kDa. Like both ACF and CHRAC, this complex organizes randomly deposited histones into a regularly spaced array. The remaining three forms include two novel ISWI complexes distinct from known ISWI complexes plus a histone-dependent ATPase complex. This comprehensive biochemical characterization of ISWI underscores the evolutionary conservation of the ACF/CHRAC family.
authors.affiliation: Laboratory of Molecular Embryology, NICHD, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: D
authors.initials: D
authors.lastname: Guschin
authors.forename: T M
authors.initials: TM
authors.lastname: Geiman
authors.forename: N
authors.initials: N
authors.lastname: Kikyo
authors.forename: D J
authors.initials: DJ
authors.lastname: Tremethick
authors.forename: A P
authors.initials: AP
authors.lastname: Wolffe
authors.forename: P A
authors.initials: PA
authors.lastname: Wade
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002384:Catalysis; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D004591:Electrophoresis, Polyacrylamide Gel; D019143:Evolution, Molecular; D015723:Gene Library; D006493:Heparin / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D015151:Immunoblotting; D008969:Molecular Sequence Data; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D014981:Xenopus; D029867:Xenopus Proteins
chemical_list: C120419:Acf protein, Drosophila; C492320:BAZ1A protein, Xenopus; D002843:Chromatin; D018076:DNA, Complementary; D029721:Drosophila Proteins; D006657:Histones; C086468:ISWI protein; D020033:Protein Isoforms; D014157:Transcription Factors; D029867:Xenopus Proteins; D006493:Heparin; D000251:Adenosine Triphosphatases