Ed on unique and shared spectra) were used for label-free quantitation. MudPIT analyses of TAP tag purified Rvb1 and Rvb2 from wild-type and PIH1 and TAH1 deletion strains show that Tah1 is present only in the presence of Pih1, whereas Pih1 is pulled-down even in the absence of Tah1 (Fig. 1A). Because our method captures complexes that are assembled in vivo, it confirms that Pih1 bridges Rvb1/Rvb2