Charge Assisted S/Se Chalcogen Bonds in SAM Riboswitches: A Combined PDB and ab Initio Study.

ABSTRACT: In this study, we provide experimental (Protein Data Bank (PDB) inspection) and theoretical (RI-MP2/def2-TZVP level of theory) evidence of the involvement of charge assisted chalcogen bonding (ChB) interactions in the recognition and folding mechanisms of S-adenosylmethionine (SAM) riboswitches. Concretely, an initial PDB search revealed several examples where ChBs between S-adenosyl methionine (SAM)/adenosyl selenomethionine (EEM) molecules and uracil (U) bases belonging to RNA take place. While these interactions are usually described as a merely Coulombic attraction between the positively charged S/Se group and RNA, theoretical calculations indicated that the σ holes of S and Se are involved. Moreover, computational models shed light on the strength and directionality properties of the

SUBMITTER: Pina MLN 

PROVIDER: S-EPMC8525861 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature