SEQUENCE COMPOSITION OF BINDING SITES IN NATIVELY UNFOLDED HUMAN PROTEINS

摘要

Natively unfolded proteins that lack any globular fold and remain very flexible in solution state exhibit diverse cellular activity and play a significant role in cell signalling and reorganization processes. Further, binding of unstructured protein to a target molecule often causes folding and conformational alteration and functional cooperativity. Engaging several algorithm and computational methods we measured the compositional aspects of the binding region of fully unfolded native human proteins. Number of binding regions was found to increase with the protein sequence length. However, most of the proteins contained multiple binding regions with variable length. The regions were distributed throughout the protein sequence and not localized. Content of different amino acids in binding regions followed a similar trend for total protein sequences; however, the regions were enriched with Ala, Gly, Leu, Phe and Tyr. Grand average of hydropathy of all the proteins was negative, although many of their binding regions showed positive values. Most of the residues in both the proteins and in the binding region favoured random-coil conformation.