Sensitivity of ribosomes from Agrobacterium tumefaciens to the ribosome-inactivating protein crotin 2 depending on the translocational state.
The GTP analog guanylylmethylene diphosphonate (GppCH2p) strongly inhibited polyuridylic acid-directed polypeptide synthesis in a cell-free translation system prepared from Agrobacterium tumefaciens. Fusidic acid increased even further the inhibitory action. The pre-translocational ribosomal complexes formed with the GppCH2p and the elongation factor G protected the ribosome against the depurinating action of crotin 2 assayed as the acid-dependent release of the RNA fragment whose terminal sequence is 5'-GAGGACCGGGAUGGAC-3'. The results allowed to conclude that the interaction of both crotin 2 and the elongation factor G with the A. tumefaciens ribosomes in the pre-translocational state must take place at overlapping, either sterically or allosterically, ribosomal sites which are equally accessible to the RIP.
Alegre
C
C
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Valladolid, Spain.
Iglesias
R
R
Ferreras
J M
JM
Citores
L
L
Girbés
T
T
D016960:Agrobacterium tumefaciens / Q000187:drug effects* / Q000235:genetics; D001483:Base Sequence; D005672:Fusidic Acid / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D008969:Molecular Sequence Data; D010452:Peptide Biosynthesis; D010455:Peptides / Q000235:genetics; D010940:Plant Proteins / Q000378:metabolism / Q000494:pharmacology*; D011072:Poly U / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D012329:RNA, Bacterial / Q000187:drug effects / Q000378:metabolism; D012335:RNA, Ribosomal / Q000187:drug effects / Q000378:metabolism; D054789:Ribosome Inactivating Proteins, Type 1; D012270:Ribosomes / Q000187:drug effects* / Q000378:metabolism
D010455:Peptides; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D054789:Ribosome Inactivating Proteins, Type 1; D011072:Poly U; C012001:polyphenylalanine; C004805:5'-guanylylmethylenebisphosphonate; D005672:Fusidic Acid; C012857:crotin II protein, Croton tiglium; D006160:Guanosine Triphosphate