Is able to cleave peptidoglycan and affects clumping and separation of bacterial cells. Is required for normal growth under stressful conditions. Is essential for nasal colonization. Highest expression during the exponential phase. Expression is increased about 3-fold by inactivation of isaA. Up-regulated by the presence of NaCl in a IsaA independent manner. Seems to be negatively regulated by SarA. Negatively regulated by the two-component systems LytSR and SaeRS whereas is positively regulated by sigma-B factor, agr and the two-component system YycFG. Cells grow slightly less well than wild-type in the presence of 2.5 M NaCl. Inactivation of both isaA and sceD genes results in a high degree of clumping and the double mutant is also attenuated for virulence. Belongs to the transglycosylase family. SceD subfamily.