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Volume 17   Issue 2   Year 2022
Structure and features of amino acid sequences of Π-modules in OB-folds

Brazhnikov E.V., Efimov A.V.

Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia 

Abstract. Stereochemical analysis has been performed for -modules from the large set of non-homologous protein structures containing the OB-fold. That module consists of two β-strands connected by a loop and placed in different sheets in such a way which looks as Greek letter . Total 70 non-homologous proteins at resolution not less than 2.5Å have been selected for the analysis from 265 suitable structures belonging to sixteen OB-fold super families. We have disclosed two types of -modules: the fist with the connecting loop containing α-helix, and second one without helix. Entrance of protein chain into second β-sheet is carried out by the same arch with conformation βββαLβp. In most cases, 85 % of total, α-positions are occupied by glycine residue, while at entrance in the loop such residues are absent. Occupancy frequency of -modules has been obtained in dependence on the loop length. Spatial pathway of structures of all modules are superimposed very well. Structural alignment of amino acid for -module sequences allows us to determine the key positions of the hydrophobic, hydrophilic, and glycine residues. 

Key words: OB-fold, β-strand, α-helix, structural motif, folding, handedness.

Table of Contents Original Article
Math. Biol. Bioinf.
doi: 10.17537/2022.17.441
published in Russian

Abstract (rus.)
Abstract (eng.)
Full text (rus., pdf)


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