The main conductance is 1nS in buffer solution. Channel-proteins have been found in gram positive and gram negative bacteria, archaea and plants. MscS channel was found after studies in E. coli spheroplasts.  The identification of the gene family necessitated for MS of small conductance was as two different channels. YggB encoding MscS and KefA encoding MscK in E. coli further confirm its role osmotic regulation. Mutagenesis studies showed that when both genes YggB and KefA were deleted MscS lost its function, but maintain MscL and MscM, but mutants deficient of YggB and MscL showed that the function of those channel is to open in respond to pressure range right before cell rupture.