Figure 4.

Mutations within the molecular chaperone Hsp104 can give rise to a ‘PSI-No-More’ phenotype. Upper: A schematic representation of the key functional domains of Hsp104 showing the two nucleotide binding domains (ATP; NBD1/NBD2) and the N-terminal (NTD) and C-terminal (CTD) domains plus the linker region between the two NBDs. The proposed functional roles of the different domains are indicated below. See refs. ⁴⁵ and ⁴⁶ for further discussion on the functional organisation of Hsp104. Lower: mutations that have so far been described which give a ‘PNM’ phenotype. The location of the mutations is given together with an indication of whether the mutation in question is dominant or a recessive with respect to the ‘PNM’ phenotype. ND indicates that the dominance/recessive character of the mutant was not reported.¹ The single mutations K218T and K620T are also dominant/semi-dominant PNMs in some genetic backgrounds.