Ribonuclease H: Full Assignment of Backbone Proton Resonances with Heteronuclear 3D NMR and Solution Structure

Abstract

The atomic scale investigation of proteins by NMR primarily depends on the assignment of the individual resonance peaks. The assignment strategy now utilized for smaller proteins (<10 kDa) consists of two steps¹: 1) The identification of the spin system characterizing each of the amino acids by COSY and 2) The sequential connection of the identified spin systems along the amino acid sequence by NOESY. To extend the strategy to larger proteins, the overlapping of chemical shifts of the densely scattered resonance should be eliminated. A new strategy recently developed in our group utilizes heteronuclear 3D NMR^2,3 and isotope enrichment to a large extent to solve the problem.