Sensitivity of translation by Brevibacterium lactofermentum ribosomes to type 1 and type 2 ribosome-inactivating proteins.
An active cell-free translation system was prepared from Brevibacterium lactofermentum, a Gram-positive bacteria used in molecular cloning and protein expression. The system contained high speed postribosomal supernatant (S 370), purified ribosomes and a tRNA mixture from Escherichia coli, and synthesized polyuridylic acid-directed polyphenylalanine once optimized for mono and divalent ions, time, and temperature. The translation system was evaluated for sensitivity to several translational inhibitors including several N-glycosidase ribosome-inactivating proteins (RIPs) isolated from plants. The pattern of inhibition by RIPs resembled that observed recently for Gram-negative bacteria such as Escherichia coli and Agrobacterium tumefaciens [Girbés et al., J. Bacteriol., 175, 6721-6724 (1993)]. A typical inhibitory type 1 RIP such as crotin 2 promoted depurination of the rRNA, which upon treatment with acid aniline released a fragment of approximately 230 nucleotides. On these grounds, we propose that bacterial ribosome sensitivity to plant RIPs depends on the bacterial ribosome-specific presence of protein recognition domains in the RIP present only in some RIP but not in others.
Ferreras
J M
JM
Department of Biochemistry and Molecular Biology, Faculty of Sciences, University of Valladolid, Spain.
Alegre
C
C
Iglesias
R
R
Girbes
T
T
D001483:Base Sequence; D001951:Brevibacterium / Q000235:genetics*; D002474:Cell-Free System; D008969:Molecular Sequence Data; D010452:Peptide Biosynthesis; D010455:Peptides; D010940:Plant Proteins / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D012343:RNA, Transfer / Q000235:genetics; D012270:Ribosomes / Q000187:drug effects* / Q000378:metabolism
D010455:Peptides; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; C012001:polyphenylalanine; D012343:RNA, Transfer