 |
PDBsum entry 2dfx
|
|
|
|
References listed in PDB file
|
 |
|
Key reference
|
|
|
Title
|
|
Structural basis for sequence-Dependent recognition of colicin e5 trnase by mimicking the mRNA-Trna interaction.
|
|
|
Authors
|
|
S.Yajima,
S.Inoue,
T.Ogawa,
T.Nonaka,
K.Ohsawa,
H.Masaki.
|
|
|
Ref.
|
|
Nucleic Acids Res, 2006,
34,
6074-6082.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Colicin E5--a tRNase toxin--specifically cleaves QUN (Q: queuosine) anticodons
of the Escherichia coli tRNAs for Tyr, His, Asn and Asp. Here, we report the
crystal structure of the C-terminal ribonuclease domain (CRD) of E5 complexed
with a substrate analog, namely, dGpdUp, at a resolution of 1.9 A. Thisstructure
is the first to reveal the substrate recognition mechanism of sequence-specific
ribonucleases. E5-CRD realized the strict recognition for both the guanine and
uracil bases of dGpdUp forming Watson-Crick-type hydrogen bonds and ring
stacking interactions, thus mimicking the codons of mRNAs to bind to tRNA
anticodons. The docking model of E5-CRD with tRNA also suggests its substrate
preference for tRNA over ssRNA. In addition, the structure of E5-CRD/dGpdUp
along with the mutational analysis suggests that Arg33 may play an important
role in the catalytic activity, and Lys25/Lys60 may also be involved without His
in E5-CRD. Finally, the comparison of the structures of E5-CRD/dGpdUp and
E5-CRD/ImmE5 (an inhibitor protein) complexes suggests that the binding mode of
E5-CRD and ImmE5 mimics that of mRNA and tRNA; this may represent the
evolutionary pathway of these proteins from the RNA-RNA interaction through the
RNA-protein interaction of tRNA/E5-CRD.
|
|
|
|
|
|
|
