The Chd family of chromatin remodelers

Abstract

Chromatin remodeling enzymes contribute to the dynamic changes that occur in chromatin structure during cellular processes such as transcription, recombination, repair, and replication. Members of the chromodomain helicase DNA-binding (Chd) family of enzymes belong to the SNF2 superfamily of ATP-dependent chromatin remodelers. The Chd proteins are distinguished by the presence of two N-terminal chromodomains that function as interaction surfaces for a variety of chromatin components. Genetic, biochemical, and structural studies demonstrate that Chd proteins are important regulators of transcription and play critical roles during developmental processes. Numerous Chd proteins are also implicated in human disease.

Figure 1

Structural Domains of Subfamily I. Schematic representation of protein domains found within yeast, fly, mouse, and human Chd genes of subfamily I. Members of this subfamily are characterized by tandem chromodomains (blue rectangles), a SNF2-like ATPase domain (yellow rectangle), and a DNA binding domain (green oval). DNA activity has only been characterized for murine Chd1. All other Chd proteins in this subfamily contain putative DNA-binding domains. The chromosome location of each of the Chd genes within this subfamily is also listed. Sequence information was obtained from NCBI: ScChd1: NP_011091; dChd1: NP_477197; mChd1: NP_031716; hCHD1: NP_001261; mChd2: XP_145698; hCHD2: NP_001262. Sequence information was also obtained from Stokes et al and Woodage et al [10,32].

Figure 2

Structural Domains of Subfamily II. Schematic representation of protein domains found within fly, mouse, and human Chd genes of subfamily II. Members of this subfamily are characterized by paired PHD Zn-finger-like domains (red triangles), tandem chromodomains (blue rectangles), and a SNF2-like ATPase domain (yellow rectangle). The chromosome location of each of the Chd genes within this subfamily is also listed. Sequence information was obtained from NCBI: dChd3: NP_649154; mChd3: NP_484041; hCHD3:NP_001005271; dChd4: NP_001014591; mChd4: NP_666091; hCHD4: NP_001264.

Figure 3

Structural Domains of Subfamily III. Schematic representation of protein domains found within mouse and human Chd genes of subfamily III. Members of this subfamily are characterized by the signature sequence motifs of Chd proteins, chromodomains (blue rectangles) and a SNF2-like ATPase domain (yellow rectangle). Additional domains have also been predicted for several members of this subfamily, including paired PHD Zn-finger-like domains (red triangles), BRK domains (purple diamonds), CR1-3 domains (red rectangles), SANT domains (blue circle), and DNA-binding domains (green oval). The chromosome location of each of the Chd genes within this subfamily is also listed. Sequence information was obtained from NCBI: mChd5: XP_900117; hCHD5: NP_056372; mChd6: NP_775544; hCHD6: NP_115597; mChd7: XP_910521; hCHD7: NP_060250; mChd8: XP_619244; hCHD8: NP_065971.1; mChd9: NP_796198; hCHD9: NP_079410. Information regarding the structural domains was also obtained from Shuster et al and Shur et al [39,40].