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PDBsum entry 1mt4
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References listed in PDB file
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Key reference
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Title
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Structure of 23s rrna hairpin 35 and its interaction with the tylosin-Resistance methyltransferase rlmaii.
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Authors
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I.Lebars,
S.Yoshizawa,
A.R.Stenholm,
E.Guittet,
S.Douthwaite,
D.Fourmy.
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Ref.
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EMBO J, 2003,
22,
183-192.
[DOI no: ]
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PubMed id
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Abstract
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The bacterial rRNA methyltransferase RlmAII (formerly TlrB) contributes to
resistance against tylosin-like 16-membered ring macrolide antibiotics. RlmAII
was originally discovered in the tylosin-producer Streptomyces fradiae, and
members of this subclass of methyltransferases have subsequently been found in
other Gram-positive bacteria, including Streptococcus pneumoniae. In all cases,
RlmAII methylates 23S rRNA at nucleotide G748, which is situated in a stem-loop
(hairpin 35) at the macrolide binding site of the ribosome. The conformation of
hairpin 35 recognized by RlmAII is shown here by NMR spectroscopy to resemble
the anticodon loop of tRNA. The loop folds independently of the rest of the 23S
rRNA, and is stabilized by a non-canonical G-A pair and a U-turn motif,
rendering G748 accessible. Binding of S.pneumoniae RlmAII induces changes in NMR
signals at specific nucleotides that are involved in the methyltransferase-RNA
interaction. The conformation of hairpin 35 that interacts with RlmAII is
radically different from the structure this hairpin adopts within the 50S
subunit. This indicates that the hairpin undergoes major structural
rearrangement upon interaction with ribosomal proteins during 50S assembly.
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Figure 5.
Figure 5 (A) View of hairpin 35 solution structure. (B) View of
the crystal structure of tRNA^Phe anticodon stem -loop. All
heavy atoms are displayed. Bases are colored in light blue with
nitrogen and oxygen atoms in dark blue and red, respectively.
Hydrogen bonds that contribute to stabilize the U-turn
conformation are represented as dashed lines.
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Figure 6.
Figure 6 Two different views of the hairpin 35 loop RNA
indicating nucleotides involved in the interaction with RlmA^II
methyltransferase. Nucleotides for which NMR signals broaden
upon binding to RlmA^II are highlighted in yellow.
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The above figures are
reprinted
from an Open Access publication published by Macmillan Publishers Ltd:
EMBO J
(2003,
22,
183-192)
copyright 2003.
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Headers
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