title: The incorporation of the novel histone variant H2AL2 confers unusual structural and functional properties of the nucleosome.
abstract: In this work we have studied the properties of the novel mouse histone variant H2AL2. H2AL2 was used to reconstitute nucleosomes and the structural and functional properties of these particles were studied by a combination of biochemical approaches, atomic force microscopy (AFM) and electron cryo-microscopy. DNase I and hydroxyl radical footprinting as well as micrococcal and exonuclease III digestion demonstrated an altered structure of the H2AL2 nucleosomes all over the nucleosomal DNA length. Restriction nuclease accessibility experiments revealed that the interactions of the H2AL2 histone octamer with the ends of the nucleosomal DNA are highly perturbed. AFM imaging showed that the H2AL2 histone octamer was complexed with only approximately 130 bp of DNA. H2AL2 reconstituted trinucleosomes exhibited a type of a 'beads on a string' structure, which was quite different from the equilateral triangle 3D organization of conventional H2A trinucleosomes. The presence of H2AL2 affected both the RSC and SWI/SNF remodeling and mobilization of the variant particles. These unusual properties of the H2AL2 nucleosomes suggest a specific role of H2AL2 during mouse spermiogenesis.
authors.affiliation: Université Joseph Fourier - Grenoble 1, INSERM Institut Albert Bonniot, U823, Site Santé-BP 170, 38042 Grenoble Cedex 9, France.
authors.forename: Sajad Hussain
authors.initials: SH
authors.lastname: Syed
authors.forename: Mathieu
authors.initials: M
authors.lastname: Boulard
authors.forename: Manu Shubhdarshan
authors.initials: MS
authors.lastname: Shukla
authors.forename: Thierry
authors.initials: T
authors.lastname: Gautier
authors.forename: Andrew
authors.initials: A
authors.lastname: Travers
authors.forename: Jan
authors.initials: J
authors.lastname: Bednar
authors.forename: Cendrine
authors.initials: C
authors.lastname: Faivre-Moskalenko
authors.forename: Stefan
authors.initials: S
authors.lastname: Dimitrov
authors.forename: Dimitar
authors.initials: D
authors.lastname: Angelov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D042002:Chromatin Assembly and Disassembly; D020285:Cryoelectron Microscopy; D018983:DNA Footprinting; D003850:Deoxyribonuclease I; D005090:Exodeoxyribonucleases; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D017665:Hydroxyl Radical; D008297:Male; D051379:Mice; D008836:Micrococcal Nuclease; D018625:Microscopy, Atomic Force; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D006657:Histones; D009707:Nucleosomes; D020033:Protein Isoforms; D017665:Hydroxyl Radical; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III; D003850:Deoxyribonuclease I; D008836:Micrococcal Nuclease