passages.id: split_6_test_406_passage
passages.type: progene_text
passages.text: Whereas wild - type human HSF1 is restrained as an inactive monomer in yeast that is unable to substitute for the essential yeast HSF protein , mutations in the linker region between the DNA binding domain and the first coiled - coil allow HSF1 to homotrimerize and rescue the viability defect of a hsfDelta strain .