The eubacterial chromosome encodes various addiction modules that control global
levels of translation through RNA degradation. Crystal structures of the
Escherichia coli YefM2 (antitoxin)-YoeB (toxin) complex and the free YoeB toxin
have been determined. The structure of the heterotrimeric complex reveals an
asymmetric disorder-to-order recognition strategy, in which one C terminus of
the YefM homodimer exclusively interacts with an atypical microbial ribonuclease
(RNase) fold of YoeB. Comparison with the YefM-free YoeB structure indicates a
conformational rearrangement of the RNase catalytic site of YoeB, induced by
interaction with YefM. Complementary biochemical experiments demonstrate that
the YoeB toxin has an in vitro RNase activity that preferentially cleaves at the
3' end of purine ribonucleotides.
Figure 2.
Figure 2. Structure of the YefM-YoeB Heterotrimer Complex
Figure 5.
Figure 5. Protein-Protein Interactions between YefM and YoeB
The above figures are
reprinted
by permission from Cell Press:
Mol Cell
(2005,
19,
497-509)
copyright 2005.
