ATP-dependent DNA helicase, also known as reptin; conserved component of multiple complexes including the INO80 complex, the Swr1 complex, the R2TP complex (Rvb1-Rvb2-Tah1-Pih1) and the TTT Hsp90 cochaperone complex that is involved in chromatin remodeling and telomeric chromatin regulation; involved in multiple processes such as chromatin remodeling, box C/D snoRNP assembly, and RNA polymerase II assembly; member of the AAA+ and RuvB protein families, similar to Rvb1p