Possesses intrinsic ATP-dependent nucleosome-remodeling activity. Constitutes the catalytic subunit of several complexes capable of forming ordered nucleosome arrays on chromatin (By similarity). Involved in the formation of nucleosome distribution patterns (PubMed:24606212). Required for the maintenance of the plant vegetative phase. In association with RLT1 or RLT2 may prevent the early activation of the vegetative-to-reproductive transition by regulating key genes that contribute to flower timing, such as FT, SEP1, SEP3, AGL8/FUL, SOC1 and FLC (PubMed:22694359). Necessary to acquire heat stress (HS) memory (PubMed:27680998). Interacts with RLT1 (PubMed:22694359). Binds to FGT1 (PubMed:27680998). A number of isoforms are produced. According to EST sequences. Highly expressed in growing tissues such as inflorescence and flower meristems, young leaves and floral organs. Expressed in roots, rosette and cauline leaves, stems, flowers, inflorescences and siliques. No visible phenotype under normal growth conditions, but the double mutant plants chr11-1 and chr17-1 are very small and display early flowering and sterility (PubMed:22694359). Premature decline of expression of HSA32, HSP18.2, HSP21, HSP22 and HSP101 after HS in the double mutant plants chr11-1 and chr17-1 (PubMed:27680998). Belongs to the SNF2/RAD54 helicase family. ISWI subfamily. Truncated N-terminus.