Involved in formation and maintenance of cell shape. Required for the spatial organization of components of the peptidoglycan-synthesizing holoenzyme in the periplasm and peptidoglycan synthetic activity. Interacts with penicillin-binding proteins (PBP2, PBP1a, PBP1b, PBP2a and PBP2b). Interacts with outer membrane proteins belonging to the TonB-dependent receptor family of transport proteins. Localizes in helical or banded patterns along the cell length. This localization requires a normal cell shape, but is not disrupted in the absence of intracellular filaments formed by MreB. Affects the localization of MltA, MipA and PBP2. In the case of MltA and MipA no polar localization is observed, and in that of PBP2 the banded localization pattern is lost. Depletion of both MreC and RodA results in defects in stalk growth and mutant cells expand relative to wild-type cells. They appear to arrest in expansion along the long axis of the cell. Belongs to the MreC family.