title: Sequence repeats and protein structure.
abstract: Repeats are frequently found in known protein sequences. The level of sequence conservation in tandem repeats correlates with their propensities to be intrinsically disordered. We employ a coarse-grained model of a protein with a two-letter amino acid alphabet, hydrophobic (H) and polar (P), to examine the sequence-structure relationship in the realm of repeated sequences. A fraction of repeated sequences comprises a distinct class of bad folders, whose folding temperatures are much lower than those of random sequences. Imperfection in sequence repetition improves the folding properties of the bad folders while deteriorating those of the good folders. Our results may explain why nature has utilized repeated sequences for their versatility and especially to design functional proteins that are intrinsically unstructured at physiological temperatures.
authors.affiliation: Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Hanoi 10000, Vietnam.
authors.forename: Trinh X
authors.initials: TX
authors.lastname: Hoang
authors.forename: Antonio
authors.initials: A
authors.lastname: Trovato
authors.forename: Flavio
authors.initials: F
authors.lastname: Seno
authors.forename: Jayanth R
authors.initials: JR
authors.lastname: Banavar
authors.forename: Amos
authors.initials: A
authors.lastname: Maritan
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D008969:Molecular Sequence Data; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry*; D020449:Repetitive Sequences, Amino Acid; D020539:Sequence Analysis, Protein / Q000379:methods*; D013329:Structure-Activity Relationship; D013696:Temperature
chemical_list: D000596:Amino Acids; D011506:Proteins