Reduced dimensionality 3D HNCAN for unambiguous HN, CA and N assignment in proteins
 

Reduced dimensionality 3D HNCAN for unambiguous HN, CA and N assignment in proteins


Publication year: 2012
Source:Journal of Magnetic Resonance</br>
Manoj Kumar Rout, Pushpa Mishra, Hanudatta S. Atreya, Ramakrishna V. Hosur</br>
We present here an improvisation of HNN (Panchal, Bhavesh et al., 2001) called RD 3D HNCAN for backbone (HN, CA and 15N) assignment in both folded and unfolded proteins. This is a reduced dimensionality experiment which employs CA chemical shifts to improve dispersion. Distinct positive and negative peak patterns of various triplet segments along the polypeptide chain observed in HNN are retained and these provide start and check points for the sequential walk. Because of co-incrementing of CA and 15N, peaks along one of the dimensions appear at sums and differences of the CA and 15N chemical shifts. This changes the backbone assignment protocol slightly and we present this in explicit detail. The performance of the experiment has been demonstrated using Ubiquitin and Plasmodium falciparum P2 proteins. The experiment is particularly valuable when two neighboring amino acid residues have nearly identical backbone 15N chemical shifts.
Graphical Abstract

http://ars.sciencedirect.com/content...000572-fx1.jpg Graphical abstract Highlights

? 3D HNCAN incorporates CA and N co-evolution in HNN. ? Provides HN, N and CA backbone assignments. ? Reduced dimensionality enhances spectral dispersion.</br>
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Source: Journal of Magnetic Resonance