nucleotide-binding domain (NBD) of the actin-related protein 4 (Arp4)-like subfamily
The Arp4-like subfamily includes Arp4, also called actin-like protein 4, from fungi and plants. Saccharomyces cerevisiae Arp4 acts synergistically with Arp8 to depolymerize F-actin; it binds ATP, but unlike conventional actin, does not form filaments. It is a component of the NuA4 histone acetyltransferase complex, the chromatin-remodeling INO80 complex and the SWR1 chromatin remodeling complex. Arabidopsis thaliana Arp4 is involved in several developmental processes including organization of plant organs, flowering time, anther development, flower senescence and fertility, probably by regulating the chromatin structure. This family also includes human homologs of yeast and plant, which are actin-like protein 6A (encoded by the ACTL6A gene; also known as ArpNbeta, 53 kDa BRG1-associated factor A/BRG1-associated factor 53A/BAF35A, and INO80 complex subunit K/INO80K) and actin-like protein 6B (encoded by the ACTL6B gene; also known as ArpNalpha, 53 kDa BRG1-associated factor B/BRG1-associated factor 53B/BAF35B). ACTL6A and ACTL6B are involved in transcriptional activation and repression of select genes by chromatin remodeling (alteration of DNA-nucleosome topology). They are components of numerous complexes with chromatin remodeling and histone acetyltransferase activity. ACTL6A is also a putative core component of the chromatin remodeling INO80 complex which is involved in transcriptional regulation, DNA replication and probably DNA repair. Schizosaccharomyces pombe actin-related protein 42 (Arp42) is also included in this family. It is also a component of SWI/SNF and RSC complexes.
Jiyao W et al.(2023). "The conserved domain database in 2023.",