TY - JOUR T1 - Intrinsically Disordered Regions May Lower the Hydration Free Energy in Proteins: A Case Study of Nudix Hydrolase in the Bacterium Deinococcus radiodurans A1 - Awile, Omar A1 - Krisko, Anita A1 - Sbalzarini, Ivo F. A1 - Zagrovic, Bojan Y1 - 2010/07/15 N2 - Author Summary Intrinsically disordered proteins and protein segments carry out a wide range of important biological functions despite their lack of permanent tertiary structure. Using advanced computational methods we study the biophysical properties of the intrinsically disordered regions in the enzyme nudix hydrolase from the desiccation- and radiation-resistant bacterium D. radiodurans. Interestingly, these regions are absent in homologue proteins in non-extremophile bacteria, suggesting that they might be involved in helping the key rescue-and-repair proteins in D. radiodurans, such as nudix hydrolase, adapt to the extreme absence of water. We show that the disordered regions in nudix hydrolase enlarge the overall surface of the enzyme, and most importantly, increase its overall affinity for water (i.e. its hydrophilicity). We suggest a novel hypothesis that this, indeed, may be the principal function of disordered regions in some cases: they increase the chances of the protein to be located in the remaining water patches in the desiccated cell, where it is protected from the desiccation effects and can function normally. JF - PLOS Computational Biology JA - PLOS Computational Biology VL - 6 IS - 7 UR - https://doi.org/10.1371/journal.pcbi.1000854 SP - e1000854 EP - PB - Public Library of Science M3 - doi:10.1371/journal.pcbi.1000854 ER -