title: The dMi-2 chromodomains are DNA binding modules important for ATP-dependent nucleosome mobilization.
abstract: Drosophila Mi-2 (dMi-2) is the ATPase subunit of a complex combining ATP-dependent nucleosome remodelling and histone deacetylase activities. dMi-2 contains an HMG box-like region, two PHD fingers, two chromodomains and a SNF2-type ATPase domain. It is not known which of these domains contribute to nucleosome remodelling. We have tested a panel of dMi-2 deletion mutants in ATPase, nucleosome mobilization and nucleosome binding assays. Deletion of the chromodomains impairs all three activities. A dMi-2 mutant lacking the chromodomains is incorporated into a functional histone deacetylase complex in vivo but has lost nucleosome-stimulated ATPase activity. In contrast to dHP1, dMi-2 does not bind methylated histone H3 tails and does not require histone tails for nucleosome binding. Instead, the dMi-2 chromodomains display DNA binding activity that is not shared by other chromodomains. Our results suggest that the chromodomains act at an early step of the remodelling process to bind the nucleosome substrate predominantly via protein-DNA interactions. Furthermore, we identify DNA binding as a novel chromodomain-associated activity.
authors: Adolf-Butenandt-Institut, Molekularbiologie, Ludwig-Maximilians-Universität, Schillerstrasse 44, D-80336 München, Germany.
authors: Karim
authors: K
authors: Bouazoune
authors: Angelika
authors: A
authors: Mitterweger
authors: Gernot
authors: G
authors: Längst
authors: Axel
authors: A
authors: Imhof
authors: Asifa
authors: A
authors: Akhtar
authors: Peter B
authors: PB
authors: Becker
authors: Alexander
authors: A
authors: Brehm
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000737:chemistry* / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D004330:Drosophila / Q000378:metabolism*; D029721:Drosophila Proteins; D006657:Histones / Q000032:analysis; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000502:physiology*; D021122:Protein Subunits; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D001324:Autoantigens; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006657:Histones; C116095:Mi-2 protein, Drosophila; D009707:Nucleosomes; D021122:Protein Subunits; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases