Forms membrane-associated dynamic filaments that are essential for cell shape determination (PubMed:16950129, PubMed:19659933). Acts by regulating cell wall synthesis and cell elongation, and thus cell shape (PubMed:16950129, PubMed:19659933). A feedback loop between cell geometry and MreBH localization may maintain elongated cell shape by targeting cell wall growth to regions of negative cell wall curvature (By similarity). Filaments rotate around the cell circumference in concert with the cell wall synthesis enzymes. The process is driven by the cell wall synthesis machinery and does not depend on MreBH polymerization (PubMed:21636745, PubMed:21636744). Organizes peptidoglycan synthesis in the lateral cell wall (PubMed:19659933). Required for the localization of the cell wall hydrolase LytE into the cylindrical part of the cell wall (PubMed:16950129). Forms polymers (PubMed:16950129). Forms a complex with Mbl and MreB (PubMed:19659933). Interacts with the C-terminal catalytic domain of LytE (PubMed:16950129). Membrane-associated. Colocalizes with MreB and Mbl (PubMed:16950129). Present in detergent-resistant membrane (DRM) fractions that may be equivalent to eukaryotic membrane rafts; these rafts include proteins involved in signaling, molecule trafficking and protein secretion (PubMed:22882210). Expression is sigma I-dependent. Disruption of the gene leads to cells that are curved, bent at irregular angles and affected in length and width. B.subtilis has three MreB paralogs: MreB, Mbl and MreBH. All paralogs have the ability to support rod-shaped cell growth normal conditions. The multiplicity of paralogs becomes important under stress conditions. They are probably used to allow cells to maintain proper growth and morphogenesis under changing conditions. Belongs to the FtsA/MreB family.