An Analytical Review of the Structural Features of Pentatricopeptide Repeats: Strategic Amino Acids, Repeat Arrangements and Superhelical Architecture.

ABSTRACT: Tricopeptide repeats are common in natural proteins, and are exemplified by 34- and 35-residue repeats, known respectively as tetratricopeptide repeats (TPRs) and pentatricopeptide repeats (PPRs). In both classes, each repeat unit forms an antiparallel bihelical structure, so that multiple such units in a polypeptide are arranged in a parallel fashion. The primary structures of the motifs are nonidentical, but amino acids of similar properties occur in strategic positions. The focus of the present work was on PPR, but TPR, its better-studied cousin, is often included for comparison. The analyses revealed that critical amino acids, namely Gly, Pro, Ala and Trp, were placed at distinct locations in the higher order structure of PPR domains. While most TPRs occur in repeats of three, the PPRs

SUBMITTER: Barik S 

PROVIDER: S-EPMC8160929 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature