ISSN:
1573-5001
Keywords:
Labeled RNA
;
Triple resonance
;
HeteroTOCSY
;
Assignment
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary A new 1H−13C−31P triple resonance experiment is described which allows unambigous sequential backbone assignment in 13C-labeled oligonucleotides via through-bond coherence transfer from 31P via 13C to 1H. The approach employs INEPT to transfer coherence from 31P to 13C and homonuclear TOCSY to transfer the 13C coherence through the ribose ring, followed by 13C to 1H J-cross-polarisation. The efficiencies of the various possible transfer pathways are discussed. The most efficient route involves transfer of 31Pi coherence via C4′i and C4′i-1, because of the relatively large J′PC4 couplings involved. Via the homonuclear and heteronuclear mixing periods, the C4′i and C4′i-1 coherences are subsequently transferred to, amongst others, H1′i and H1′i-1, respectively, leading to a 2D 1H−31P spectrum which allows a sequential assignment in the 31P−1H1′ region of the spectrum, i.e. in the region where the proton resonances overlap least. The experiment is demonstrated on a 13C-labeled RNA hairpin with the sequence 5′(GGGC-CAAA-GCCU)3′.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00227472
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