NMR Analysis of Apo Glutamine-Binding Protein Exposes Challenges in the Study of Interdomain Dynamics.

ABSTRACT: Glutamine-binding protein (GlnBP) displays an apo, "open" and a holo, "closed" crystal form, mutually related by a rigid-body reorientation of its domains. A fundamental question about such large-scale conformational transitions, whether the closed state exists in the absence of ligand, is controversial in the case of GlnBP. NMR observations have indicated no evidence of the closed form, whereas experimentally validated computations have suggested a remarkable ca. 40 % population. Herein, a paramagnetic NMR strategy designed to detect the putative apo-closed species shows that a major population of the latter is highly improbable. Further, NMR residual dipolar couplings collected under three anisotropic conditions do not reveal differential domain alignment and establish that the average s

SUBMITTER: Kooshapur H 

PROVIDER: S-EPMC6848765 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature