According to the literature, members of the structural domains which comprise this superfamily correspond to the structure of domain 1 of MscL, acronym which stands for large-conductance mechanosensitive channel. This domain is annotated in both Pfam (PFAM:PF01741) and InterPro (INTERPRO:IPR001185). However, both databases annotate this as a single chain domain whilst CATH subdivides it in two distinct domains. Thus, the term domain 1 has been included in the name of the superfamily for specificity.

MscL forms a homopentameric channel and, as we can see from the structure of this superfamilies's representative domain, each subunit is comprised of two transmembrane alpha helices PMID:19701184. This channel opens in response to stretch forces in the membrane lipid bilayer and it is believed to be involved in osmoregulation.