title: YbxF, a protein associated with exponential-phase ribosomes in Bacillus subtilis.
abstract: The ybxF gene is a member of the streptomycin operon in a wide range of gram-positive bacteria. In Bacillus subtilis, it codes for a small basic protein (82 amino acids, pI 9.51) of unknown function. We demonstrate that, in B. subtilis, YbxF localizes to the ribosome, primarily to the 50S subunit, with dependence on growth phase. Based on three-dimensional structures of YbxF generated by homology modeling, we identified helix 2 as important for the interaction with the ribosome. Subsequent mutational analysis of helix 2 revealed Lys24 as crucial for the interaction. Neither the B. subtilis ybxF gene nor its paralogue, the ymxC gene, is essential, as shown by probing DeltaybxF, DeltaymxC, or DeltaybxF DeltaymxC double deletion strains in several functional assays.
authors.affiliation: Institute of Molecular Genetics ASCR, Vídenská 1083, 142 20 Prague 4, Czech Republic.
authors.forename: Ludĕk
authors.initials: L
authors.lastname: Sojka
authors.forename: Vladimír
authors.initials: V
authors.lastname: Fucík
authors.forename: Libor
authors.initials: L
authors.lastname: Krásný
authors.forename: Ivan
authors.initials: I
authors.lastname: Barvík
authors.forename: Jirí
authors.initials: J
authors.lastname: Jonák
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003198:Computer Simulation; D017353:Gene Deletion; D005798:Genes, Bacterial; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins