A highly hydrophilic segment in yeast CPSF-100 (Ydh1p). (a) Residues 401–650 of yeast CPSF-100 (Ydh1p) are highly hydrophilic. Negatively charged residues (Asp and Glu) are shown in red, positively charged residues (Lys and Arg) in blue and hydrophilic residues (Ser, Thr, Asn, Gln, and His) in magenta. (b). Schematic drawing of the domain architecture of yeast CPSF-100 (Ydh1p). The metallo-β-lactamase domain is shown in cyan, the β-CASP domain in yellow (Callebaut et al., 2002 ▶; Mandel et al., 2006 ▶) and the hydrophilic segment in gray.