During developmental cell division in sporulation-committed aerial hyphae of streptomycetes, up to a hundred septa are simultaneously produced, in close harmony with synchromous chromosome... Show moreDuring developmental cell division in sporulation-committed aerial hyphae of streptomycetes, up to a hundred septa are simultaneously produced, in close harmony with synchromous chromosome condensation and segregation. Several unique protein families are involved in the control of this process, including that of the SsgA-like proteins (SALPs). While SsgA and SsgB are essential for sporulation-specific cell division in S. coelicolor, SsgC-G are responsible for correct DNA segregation/condensation, spore wall synthesis, autolytic spore separation, or exact septum localisation. The SALPs are a novel protein family that acts through timing and localisation of the activity of penicillin-binding proteins and autolysins, thus controlling important steps during the initiation and the completion of sporulation. The formation of septa is initiated by the formation of a ring of the tubulin-like protein FtsZ (the Z-ring), functioning as a scaffold for the construction of septa. Subsequently, other cell division proteins are recruited to the Z-ring, forming the divisome. In S. coelicolor, the cell division proteins FtsE and FtsX participate during autolytic spore separation, and most likely function by re-importing peptidoglycan subunits for recycling. The cytoskeletal protein MreB is involved in cell shape determination and chromosome segregation in many rod-shaped bacteria. In S. coelicolor, the actin-like proteins MreB and Mbl are not essential for vegetative growth but exert their function in the formation of environmentally stable spores, thereby primarily influencing the assembly of the spore wall. Show less