title: Characterization of nucleotide-binding sites on the chloroplast coupling factor 1 using two photolabile analogs.
abstract: Nucleotide-binding sites on the chloroplast coupling factor 1 (CF1) have been probed using two photoreactive ADP analogs: 2-azido-ADP (2-N3-ADP) and 2',3'-O-(4-benzoyl)benzoyl-ADP (Bz-ADP). Photolabeling of the isolated CF1 with 2-N3-ADP results in incorporation of the analog exclusively into the beta-subunit of the enzyme. The location of the nucleotide-binding site(s) within the beta-subunit of the CF1 was investigated using peptide mapping. Within the discrimination limits of this technique, it is concluded that the azido- and benzoyl-modified analogs both bind to the same conformation of the nucleotide-binding site(s) of soluble CF1. Bz-ADP, however, labels the binding site(s) on membrane-bound CF1 in a slightly different manner.
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D001386:Azides; D001665:Binding Sites; D002736:Chloroplasts / Q000201:enzymology*; D007425:Intracellular Membranes / Q000201:enzymology; D046911:Macromolecular Substances; D008970:Molecular Weight; D009711:Nucleotides / Q000378:metabolism; D010944:Plants / Q000201:enzymology; D011485:Protein Binding; D006180:Proton-Translocating ATPases / Q000378:metabolism*
chemical_list: D001386:Azides; D046911:Macromolecular Substances; D009711:Nucleotides; D000244:Adenosine Diphosphate; C022295:2-azidoadenosine 3',5'-diphosphate; C045291:3'-O-(4-benzoyl)benzoyladenosine diphosphate; D006180:Proton-Translocating ATPases