Weak and Transient Protein Interactions Determined by Solid‐State NMR

Abstract

Despite their roles in controlling many cellular processes, weak and transient interactions between large structured macromolecules and disordered protein segments cannot currently be characterized at atomic resolution by X-ray crystallography or solution NMR. Solid-state NMR does not suffer from the molecular size limitations affecting solution NMR, and it can be applied to molecules in different aggregation states, including non-crystalline precipitates and sediments. A solid-state NMR approach based on high magnetic fields, fast magic-angle sample spinning, and deuteration provides chemical-shift and relaxation mapping that enabled the characterization of the structure and dynamics of the transient association between two regions in an 80 kDa protein assembly. This led to direct verification of a mechanism of regulation of E. coli DNA metabolism.

Glutamate promotes SSB protein–protein Interactions via intrinsically disordered regions

“…We proposed that this could result from the acidic tip of one SSB tetramer interacting with an unoccupied ssDNA binding site of a neighboring tetramer [27]. Such interactions have been demonstrated at high SSB concentrations [33]. However, this type of interaction is precluded in the (SSB) 65 mode since all ssDNA binding sites are occupied by DNA.…”

Rapid access to RNA resonances by proton-detected solid-state NMR at >100 kHz MAS

“…However, all building blocks of the pulse sequences have been shown to perform also on non-crystalline formulations. 18 , 31 – 33 Given the difficulty of obtaining good-diffracting crystals for large RNA–protein complexes, we anticipate that these results will strengthen the role of MAS NMR in RNA structural biology, and more generally provide momentum in the atomic-level description of structure and dynamics of RNA.…”

Methods for Physical Characterization of Phase-Separated Bodies and Membrane-less Organelles

“…In a recent study, Dannatt, et al [146], showed that E. Coli single-stranded DNA binding protein readily forms hydrogels in vitro . Using ssNMR methods to measure CSPs and 15 N R 1ρ values, showed that the C-terminal acidic motif transiently interacts with the DNA binding groove, thus rationalizing the observed hydrogelation and providing a mechanism for the observed auto-inhibition [146].…”