Available online at www.sciencedirect.com ScienceDirect Relating sequence encoded information to form and function of intrinsically disordered proteins Rahul K Das, Kiersten M Ruff and Rohit V Pappu Intrinsically disordered proteins (IDPs) showcase the of archetypal IDPs. CCRs enable the assignments of importance of conformational plasticity and heterogeneity in conformational descriptors and inferences regarding the protein function. We summarize recent advances that connect amplitudes of conformational fluctuations of IDPs. These information encoded in IDP sequences to their conformational insights are relevant because amino acid compositions are properties and functions. We focus on insights obtained often well conserved among orthologs of IDPs even if their through a combination of atomistic simulations and biophysical sequences are poorly conserved [42,43]. measurements that are synthesized into a coherent framework using polymer physics theories. Compositional classes of IDPs Address Amino acid compositions of IDPs are characterized by Department of Biomedical Engineering and Center for Biological distinct biases [5]. They are deficient in canonical hydro- Systems Engineering, Washington University in St. Louis, One Brookings phobic residues and enriched in polar and charged resi- Drive, Campus Box 1097, St. Louis, MO 63130, USA dues. Accordingly, IDPs fall into three distinct compositional classes that reflect the fraction of charged Corresponding author: Pappu, Rohit V (
[email protected]) versus polar residues. The distinct classes are polar tracts, polyampholytes, and polyelectrolytes [41] (see Figure 1). Polar Current Opinion in Structural Biology 2015, 32:102–112 tracts are deficient in charged, hydrophobic, and proline residues. They are enriched in polar amino acids such as This review comes from a themed issue on Sequences and topology Asn, Gly, Gln, His, Ser, and Thr.