Nature's Shortcut to Protein Folding.

Area of Science:

• Biophysics
• Computational Biology
• Molecular Biology

Background:

• Protein folding is crucial for biological function.
• The process of achieving a specific 3D structure from a linear sequence is complex.
• For proteins >100 amino acids, an unaided search for the native structure is computationally challenging.

Purpose of the Study:

• To present and support the "Nature's Shortcut" hypothesis for protein folding.
• To propose that early establishment of nonlocal contacts (protein loops) guides folding.
• To unify experimental and theoretical models of protein folding.

Main Methods:

• Experimental testing of the loop hypothesis (LH) using time-resolved Förster resonance energy transfer (TR-FRET).
• Application of the sequential collapse model (SCM) for theoretical predictions.
• Utilizing primary sequence information to predict key nonlocal contacts.

Main Results:

• Experimental data for adenylate kinase are consistent with the LH and SCM predictions.
• The loop hypothesis (LH) and sequential collapse model (SCM) offer a unified view of protein folding.
• The SCM successfully predicts critical nonlocal contacts from primary sequence data.

Conclusions:

• Nature's Shortcut, mediated by nonlocal contacts, provides an efficient pathway for protein folding.
• The proposed mechanism bypasses the need for an exhaustive search of conformational space.
• This framework offers a testable model for understanding and predicting protein folding pathways.