Source was cell extract of S2 cell line; bait produced from transfected construct; prey produced from transfected construct.

Vps39 specifically binds the GTP-bound state of Rab2 (not GDP-locked Rab2, or either form of Rab7).

Source was yeast cell line; bait produced as transgenic fusion protein; prey produced as transgenic fusion protein (prey was previously cloned reagent).

Vps39 specifically binds the GTP-bound state of Rab2 (not GDP-locked Rab2, or either form of the other 16 Rab proteins tested).

Two-hybrid system: yeast GAL4-BD/GAL4-AD

Interaction in vitro; bait produced as a recombinant fusion protein in bacterial system; prey derived from S2 cell extract (endogenous gene).

Specificity S-score=20.9.

Constitutively active (GTP-locked) form of Rab was used for pull down. Parallel pull downs performed for several Rabs proteins in this study. Yield was measured using spectral counts. A specificity score (S score) was calculated, where greater weight was given to interactions seen with fewer baits.

Interaction in vitro; bait produced as a recombinant fusion protein in bacterial system; prey derived from S2 cell detergent-free extract (endogenous gene).

Specificity S-score=29.95.

Constitutively active (GTP-locked) form of Rab was used for pull down. Parallel pull downs performed for several Rabs proteins in this study. Yield was measured using spectral counts. A specificity score (S score) was calculated, where greater weight was given to interactions seen with fewer baits.

Source was yeast cell line; bait produced as transgenic fusion protein; prey produced as transgenic fusion protein (prey was previously cloned reagent).

Two-hybrid system: yeast GAL4-BD/GAL4-AD

Interaction in vitro; bait produced as a recombinant fusion protein in bacterial system; prey produced as a recombinant fusion protein in bacterial system.

GTP-bound form of Rab2 showed stronger binding to Vps39 than the GDP-bound form. Binding of Vps39 to the GDP-bound form of Rab2 was similar to background (MBP tag only control).