RT Journal Article T1 Nucleoid-associated PhaF phasin drives intracellular location and segregation of polyhydroxyalkanoate granules in Pseudomonas putida KT2442. A1 Galan, Beatriz A1 Dinjaski, Nina A1 Maestro García-Donas, María Beatriz A1 de Eugenio, Laura A1 Escapa, Isabel A1 Sanz, Jesus Miguel A1 Garcia, José luis A1 Prieto, Maria AB The PhaF is a nucleoid-associated like protein of Pseudomonas putida KT2442 involved in the polyhydroxyalkanoate (PHA) metabolism. Its primary structure shows two modular domains; the N-terminal PHA granule-binding domain (phasin domain) and the C-terminal half containing AAKP-like tandem repeats characteristic of the histone H1 family. Although the PhaF binding to PHA granules and its role as transcriptional regulator have been previously demonstrated, the cell physiology meaning of these properties remains unknown. This work demonstrates that PhaF plays a crucial role in granule localization within the cell. TEM and flow cytometry studies of cells producing granules at early growth stage demonstrated that PhaF directs the PHA granules to the centre of the cells, forming a characteristic needle array. Our studies demonstrated the existence of two markedly different cell populations in the strain lacking PhaF protein, i.e. cells with and without PHA. Complementation studies definitively demonstrated a key role of PhaF in granule segregation during the cell division ensuring the equal distribution of granules between daughter cells. In vitro studies showed that PhaF binds DNA through its C-terminal domain in a non-specific manner. All these findings suggested a main role of PhaF in PHA apparatus through interactions with the segregating chromosome. PB Blackwell SN 0950-382X YR 2011 FD 2011 LK https://hdl.handle.net/20.500.14352/95310 UL https://hdl.handle.net/20.500.14352/95310 LA eng NO Galán, B., Dinjaski, N., Maestro, B., De Eugenio, L. I., Escapa, I. F., Sanz, J. M., ... & Prieto, M. A. (2011). Nucleoid‐associated PhaF phasin drives intracellular location and segregation of polyhydroxyalkanoate granules in Pseudomonas putida KT2442. Molecular microbiology, 79(2), 402-418. NO Comunidad de Madrid NO Comisión Interministerial de Ciencia y Tecnología (España) NO European Commission DS Docta Complutense RD 12 abr 2025