Self-contacting Cys, Ser, and Thr residues in high-resolution protein crystal structures: Tertiary constraints or hydrogen bonds?

ABSTRACT: Functional groups in the side-chains of at least 10 amino acids are mainly involved in tertiary interactions. However, structural and functional significance of intra-residue interactions has not been fully recognized. In this study, we have analyzed ~5800 non-redundant high-resolution protein structures and identified 1166 self-contacts between the side-chain S-H/O-H and backbone C=O groups in Cys, Ser, and Thr residues that satisfied the geometric criteria to form hydrogen bonds. Quantum chemical calculations using model compounds were used to evaluate single point energy for 45 representative examples from different allowed regions of Ramachandran map. Relative energy profiles obtained by varying the side-chain dihedral angle χ¹ revealed that the energy difference between the

SUBMITTER: Singh P 

PROVIDER: S-EPMC11568416 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature