Table 1. Binding site matches (see text) to proteins of known structure in the LacI/RbsB family, where boldface indicates sequences without annotated ligand specificity. SWISS-PROT or GenBank identifiers are shown along with the GenBank annotation. For entries without SWISS-PROT IDs, species names are indicated. PDB structure Binding site Database annotation (ligand) match 1tlf (IPTG/lactose LACI_KLEPN lactose operon repressor 3367755 putative transcriptional regulator (Streptomyces coelicolor) 2dri (ribose) RBSB_SALTY ribose PBP RBSB_HAEIN ribose PBP 2636121 ribose PBP (Bacillus subtilis) RBSR_BACSU ribose operon repressor DEGA_BACSU probable activator of phosphoribosylpyrophosphate amidotransferase gene 2612909 LacI repressor-like protein (B. subtilis) 1byk (trehalose/ TRER_SALTY trehalose operon repressor tre-6-P) 1gca (galactose/ DGAL_CITFR D-galactose/D-glucose PBP glucose) DGAL_HAEIN D-galactose/D-glucose PBP DGAL_SALTY D-galactose/D-glucose PBP 1wet (guanine) 2961532 purine repressor (Salmonella typhimurium) PURR_HAEIN purine repressor