A transpeptidase that forms peptide cross-links between adjacent glycan strands in cell wall peptidoglycan (PG). Part of the elongasome machinery that synthesizes peripheral PG. Interacts with MreC in the elongasome. Localizes to the midcell division sites, colocalizes with StkP. Essential, it cannot be disrupted; however suppressors of the deletion can be isolated under certain growth conditions. Belongs to the transpeptidase family. Extended N-terminus.