Evolved sequence features within the intrinsically disordered tail influence FtsZ assembly and bacterial cell division

Megan C. Cohan; Ammon E. Posey; Steven J. Grigsby; Anuradha Mittal; Alex S. Holehouse; Paul J. Buske; Petra A. Levin; Rohit V. Pappu

Intrinsically disordered regions (IDRs) feature prominently in eukaryotic proteins (Dunker et al., 2002a; van der Lee et al., 2014) . These regions are associated with a range of molecular functions that contribute to an assortment of cellular processes (Dunker et al., 2002b; Iakoucheva et al., 2002; Iakoucheva et al., 2004; Wright and Dyson, 2015) . IDRs and intrinsically disordered proteins (IDPs) defy the well-established sequence-structure-function paradigm that provides a coherent framework for connecting sequence-encoded information to molecular functions for proteins that fold into well-defined three-dimensional structures (Babu, 2016) . This is because conformational heterogeneity is a defining hallmark of IDRs / IDPs (Babu et al., 2012; Forman-Kay and Mittag, 2013; Lyle et al., 2013; Wright and Dyson, 2015) . Despite this sequence-intrinsic conformational heterogeneity it has become clear that IDRs and IDPs have definable sequence-to-conformation relationships (Das et al., 2015; Forman-Kay and Mittag, 2013; Gibbs and Showalter, 2016) . The overall sizes, shapes, and amplitudes of conformational fluctuations of IDRs / IDPs are governed by compositional parameters such as the fraction of charged residues and the overall proline contents (Hofmann et al., 2012; Holehouse et al., 2017; Mao et al., 2013; Muller-Spath et al., 2010) . Additional contributions to sequence-to-conformation relationships include the linear patterning of oppositely charged residues as well as the linear patterning of proline and charged residues Martin et al., 2016) .