This domain is found at the N terminus of SMC proteins. The SMC (structural maintenance of chromosomes) superfamily proteins have ATP-binding domains at the N- and C-termini, and two extended coiled-coil domains separated by a hinge in the middle. The eukaryotic SMC proteins form two kind of heterodimers: the SMC1/SMC3 and the SMC2/SMC4 types. These heterodimers constitute an essential part of higher order complexes, which are involved in chromatin and DNA dynamics [1]. This family also includes the RecF and RecN proteins that are involved in DNA metabolism and recombination.

1: Structural maintenance of chromosomes (SMC) proteins: conserved molecular properties for multiple biological functions. Strunnikov AV, Jessberger R; Eur J Biochem 1999;263:6-13. PMID:10429180

2: SMC protein complexes and higher-order chromosome dynamics. Hirano T; Curr Opin Cell Biol 1998;10:317-322. PMID:9640531