6ciu

Publication Abstract from PubMed

We present the structure of an engineered protein-protein interface between two beta barrel proteins, which is mediated by interactions between threonine (Thr) residues. This Thr zipper structure suggests that the protein interface is stabilized by close-packing of the Thr residues, with only one inter-monomer hydrogen bond (H-bond) between two of the Thr residues. This Thr-rich interface provides a unique opportunity to study the behavior of Thr in the context of many other Thr residues. In previous work, we have shown that the side chain (chi1 ) dihedral angles of interface and core Thr residues can be predicted with high accuracy using a hard sphere plus stereochemical constraint (HS) model. Here, we demonstrate that in the Thr-rich local environment of the Thr zipper structure, we are able to predict the chi1 dihedral angles of most of the Thr residues. Some, however, are not well predicted by the HS model. We therefore employed explicitly solvated molecular dynamics (MD) simulations to further investigate the side chain conformations of these residues. The MD simulations illustrate the role that transient H-bonding to water, in combination with steric constraints, play in determining the behavior of these Thr side chains. This article is protected by copyright. All rights reserved.

"A threonine zipper that mediates protein-protein interactions: Structure and prediction".,Oi C, Treado JD, Levine ZA, Lim CS, Knecht KM, Xiong Y, O'Hern CS, Regan L Protein Sci. 2018 Sep 10. doi: 10.1002/pro.3505. PMID:30198622^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.