Table I

Pex19p and Pex19pΔCaaX have different binding properties in the b-2HS

Exponentially growing bacterial cells (strain HB101), transformed with plasmids encoding one of the indicated T18 fusion proteins (T18-hybrid) and T25 fused to either Pex19p or Pex19pΔCaaX, were assayed for β-galactosidase using o-nitrophenyl-β-d-galactopyranoside as substrate (46). Formed o-nitrophenol was measured at 420 nm and normalized for culture densities (optical density at 600 nm = 1) and time (1 h). The values given are the mean (± the S.D.) of at least three measurements performed on independent single colonies and corrected for the blank (T18 and T25 only, 3.3 ± 0.2). When the corresponding double transformants where grown on MacConkey/maltose agar plates, they appeared as white (not underlined) or red (underlined) colonies. Pex13pV164E represents a Pex13p mutant in which the valine amino acid residue at position 164 is altered to glutamate (23).

T18 hybridOptical density
T25-Pex19pT25-Pex19pΔCaaX
Pex3p 111 ± 18 117 ± 29
Pex10p0.8 ± 0.60.6 ± 0.2
Pex11pβ 59 ± 10 8.0 ± 1.7
Pex12p1.1 ± 0.81.4 ± 0.4
Pex13p1.1 ± 0.30.6 ± 0.6
Pex13pV164E 18 ± 5 15 ± 8
Pex14p 31 ± 9 39 ± 5
Pex16p 33 ± 0.3 35 ± 6