Automated Assignment of Backbone Resonances Using Residual Dipolar Couplings Acquired from a Protein with Known Structure

TL;DR

This paper introduces an automated NMR resonance assignment method that uses only residual dipolar coupling data to assign backbone resonances, estimate order tensors, and validate protein structures efficiently.

Contribution

It presents a novel RDC-only approach for backbone resonance assignment that simultaneously estimates order tensors and verifies assignment accuracy.

Findings

Successfully assigns backbone resonances using simulated RDC data

Estimates order tensors concurrently with resonance assignment

Validates the approach with simulated protein data from 1A1Z

Abstract

Resonance assignment is a critical first step in the investigation of protein structures using NMR spectroscopy. The development of assignment methods that require less experimental data is possible with prior knowledge of the macromolecular structure. Automated methods of performing the task of resonance assignment can significantly reduce the financial cost and time requirement for protein structure determination. Such methods can also be beneficial in validating a protein's solution state structure. Here we present a new approach to the assignment problem. Our approach uses only RDC data to assign backbone resonances. It provides simultaneous order tensor estimation and assignment. Our approach compares independent order tensor estimates to determine when the correct order tensor has been found. We demonstrate the algorithm's viability using simulated data from the protein domain 1A1Z.