Two-conformer equilibrium of maltose-binding protein in the absence of ligand from residual dipolar coupling analysis.

ABSTRACT: Prior analyses found good agreement between numerous residual dipolar couplings (RDCs) measured in the apo-state of maltose binding protein (MBP) and its X-ray crystal structure. However, paramagnetic relaxation enhancement (PRE) measurements on the same system reported on the presence of a small population of partially closed states in the absence of ligand, with somewhat different relative orientations of its N- and C-terminal domains. We present a protocol for RDC fitting to such a dynamic system that yielded quantitative validation of the PRE results. Our analysis is based on a multi-conformer singular value decomposition (SVD) RDC fitting procedure that provides a straightforward method for quantifying conformational equilibria, provided that high-quality RDCs and accurate coordinates

SUBMITTER: Shen Y 

PROVIDER: S-EPMC12723730 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature