Premium
Assignment of NH resonances in nucleic acids using natural abundance 15 N‐ 1 H correlation spectroscopy with spin‐echo and gradient pulses
Author(s) -
Szewczak Alexander A.,
Kellogg Gregory W.,
Moore Peter B.
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81000-p
Subject(s) - abundance (ecology) , nucleic acid , spectroscopy , nuclear magnetic resonance , chemistry , nuclear magnetic resonance spectroscopy , spin (aerodynamics) , physics , natural abundance , analytical chemistry (journal) , nuclear physics , biology , isotope , biochemistry , quantum mechanics , chromatography , fishery , thermodynamics
It is well known that 2D 15 N‐ 1 H correlation spectra can resolve overlapped imino proton resonances in the downfleld NMR spectra of nucleic acids according to their 15 N chemical shifts, and that these resonances can be assigned by base type on that basis, independent of conformation. This information can be extremely important in determining the solution structure of a nucleic acid by NMR, but previously could only be obtained using 15 N‐labeled, or very concentrated samples. Here we report the design of a gradient‐enhanced, jump‐return spin echo version of an 15 N‐ 1 H HMQC experiment (GE‐JRSE HMQC) that is sensitive enough to work on unlabeled nucleic acid samples at normal NMR concentrations. This experiment has led to the assignment of imino proton resonances with non‐Watson‐Crick chemical shifts in the spectrum of a 29 residue oligoribonucleotide that models the sarcin/ricin loop from 28S rRNA.