The sucrose binding protein (SBP) has been implicated as an important component of the sucrose uptake system in plants. SBP-mediated sucrose transport displays unique ki-netic features and theprotein isnot similar toother transport proteins. Here, we report the characterization of a member of the SBP family from soybean [Glycine max(L) Merrill] designated S64 or SBP2. Subcellular fractionation and pre-cipitation byGTP-agarose demonstrated that S64/SBP2 is a membrane-associated protein that exhibits GTP binding activity. .
