title: GTP-binding proteins in a cyanobacterium Anabaena cylindrica.
abstract: GTP-binding proteins were detected in a crude extract containing membrane components of Anabaena cylindrica. The crude extract was treated with 1% Lubrol PX and was fractionated by gel filtration. The binding of [35S]GTP gamma S to GTP-binding proteins was prevented in the presence of 0.1 mM GTP and in the presence of 0.1 mM ATP. Six fractions of these GTP-binding proteins, tentatively designated GA1 to GA6, were ADP-ribosylated by pertussis toxin. GA3, GA4 and GA5 had Km values of 10, 60 and 7 nM, respectively. The molecular weights of some of these GTP-binding proteins were reduced after being labelled with [35S]GTP gamma S.
mesh_terms: D001667:Binding, Competitive; D002462:Cell Membrane / Q000032:analysis; D002850:Chromatography, Gel; D000458:Cyanobacteria / Q000032:analysis*; D019204:GTP-Binding Proteins / Q000032:analysis* / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D013873:Thionucleotides / Q000378:metabolism
chemical_list: D013873:Thionucleotides; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins