Table 3.

Interactions of Obg and Rsb proteins by yeast two-hybrid systema

BD fusionAD fusion (ratio)
Obg′Obg
Vector, pAS2-111
X1.881.15
T0.5254.41
W5.5233.86
  • a The horizontal rows represent the Gal4 DNA BD vector (pAS2-1) either without insert DNA (row 1) or with thesigB gene depicted by a single letter (e.g., X =rsbX). The vertical rows depict the AD vector (pACT-2) encoding either the 285- to 328-amino-acid fragment of Obg, originally identified in the library screen (Obg′) or else intact Obg. Intersecting rows represent reporter gene activity (i.e., β-galactosidase expression) in a yeast strain cotransformed with both plasmids indicated by row. β-Galactosidase assays were performed on two clones from each pairing in duplicate. The results are presented as a ratio of the Rsb protein-AD fusion value from the indicated pairing divided by the value obtained from the AD fusion pairing with the pAS2-1 vector.