Streptomycetes are multicellular filamentous bacteria that grow as a mycelium, and reproduce by sporulation. Normal growth is achieved by tip extension and branching of the vegetative hyphae. As the only free-living organism that can grow without cell division, it is an important model system for the study of the divisome.

Our work led to two major new insights:

(1) SsgA and SsgB – which are unique to sporulating actinomycetes – actively recruit the cell division scaffold protein FtsZ to the septum sites during sporulation. This was the first published example of positive control of cell division.

(2) During vegetative growth, intricate membrane assemblies are formed to protect the DNA from being guillotined by the growing septum. These so-called cross-membranes play a key role in the control of cell division in the apparent absence of the nucleoid occlusion system found in other bacteria.

We will continue to provide new insights into the many unresolved issues relating to the spectacular multi-cellular life cycle of streptomycetes and other actinobacteria using a variety of techniques, including innovative imaging technologies.

• Celler, K., Koning, R.I., Willemse, J., Koster, A.J., and van Wezel, G.P. (2016) Cross-membranes orchestrate compartmentalization and morphogenesis in Streptomyces. Nat Comm 7: 11836.
• Yague, P., Willemse, J., Koning, R.I., Rioseras, B., Lopez-Garcia, M.T., Gonzalez-Quinonez, N., Lopez-Iglesias, C., Shliaha, P.V., Rogowska-Wrzesinska, A., Koster, A.J., Jensen, O.N., van Wezel, G.P., and Manteca, A. (2016) Subcompartmentalization by cross-membranes during early growth of Streptomyces hyphae. Nat Commun 7: 12467.
• Barka, E.A., Vatsa, P., Sanchez, L., Gavaut-Vaillant, N., Jacquard, C., Meier-Kolthoff, J., Klenk, H.P., Clément, C., Oudouch, Y., and van Wezel, G.P. (2016) Taxonomy, physiology, and natural products of the Actinobacteria. Microbiol Mol Biol Rev 80: 1-43
• Zhang, L., Willemse, J., Claessen, D., and van Wezel, G.P. (2016) SEpG coordinates sporulation-specific cell division and necleaoid organising in Streptomyces coelicolor. Open Biol 6: 150164.
• Chenouard, N., et al. (2014) Objective comparison of particle tracking methods. Nat Methods 11: 281-289.
• Claessen, D., Rozen, D.E., Kuipers, O.P., Sogaard-Andersen, L., and van Wezel, G.P. (2014) Bacterial solutions to multicellularity: a tale of biofilms, filaments and fruiting bodies. Nat Rev Microbiol 12: 115-124.
• Willemse, J., Borst, J.W., de Waal, E., Bisseling, T., and van Wezel, G.P. (2011) Positive control of cell division: FtsZ is recruited by SsgB during sporulation of Streptomyces. Genes Dev 25: 89-99.
• Noens, E.E., Mersinias, V., Traag, B.A., Smith, C.P., Koerten, H.K., and van Wezel, G.P. (2005) SsgA-like proteins determine the fate of peptidoglycan during sporulation of Streptomyces coelicolor. Mol Microbiol 58: 929-944

• cell division
• cell wall
• cryo-electron microscopy
• development & disease
• ftsz
• sporulation
• streptomyces