9.B.276.  The Ciliate 9 TMS Membrane Protein (C9MP) Family 

Nothing is known about the functions of the N-terminal hydrophobic domains of these proteins other than they have about 9 TMSs followed by a large hydrophilic domain. Homologues of the N-terminal transmembrane domain are found only in ciliates. However, the C-terminal hydrophilic domain is universal.  It is a chromosomal segregation ATPase, Smc (Structural maintenance of chromosomes), that binds DNA throughout much of all of the cell cycle.  The SMC (Rabaptin; neuromodulin) family includes condensin and cohesin, which structure chromosomes to enable mitosis and long-range gene regulation. The mechanism of loop formation and the implications for how these complexes ultimately shape chromosomes have been discussed (van Ruiten and Rowland 2018).