3j5v
From Proteopedia
PhuZ201 filament
Structural highlights
FunctionPHUZ_BP201 A tubulin-like GTPase that forms filaments, which are required for positioning viral DNA and capsids in the middle of the host cell for optimal replication (PubMed:28082593, PubMed:22726436, PubMed:25429514, PubMed:31199917, PubMed:28813669). The motor component of a partition system which pushes phage DNA (encased by protein gp105) to the center of the bacterial host cell (PubMed:28082593, PubMed:28813669). Also required for movement of phage capsids to the vicinity of the viral DNA and rotation of the encased viral DNA at midcell (PubMed:31199917). Forms filaments during the lytic phase, which position phage DNA at the center of the bacterial host cell (PubMed:22726436, PubMed:25429514, PubMed:31199917, PubMed:28082593, PubMed:28813669). Filaments have a three-stranded intertwined achitecture and form a spindle-like cytoskeleton within the infected cell (PubMed:24631461). Has GTPase activity (PubMed:22726436). Filaments grow at the plus end and depolymerize at the minus end, a process called treadmilling, and switch from growing in a polar manner to catastrophic depolymerization, i.e. they display dynamic instability, like tubulin. In infected host cells the filament ends close to the cell pole are relatively stable, while the other end near the phage DNA is highly dynamic (PubMed:25429514). Both capsid movement and DNA rotation probably require treadmilling (Probable).[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedTubulins are a universally conserved protein superfamily that carry out diverse biological roles by assembling filaments with very different architectures. The underlying basis of this structural diversity is poorly understood. Here, we determine a 7.1 A cryo-electron microscopy reconstruction of the bacteriophage-encoded PhuZ filament and provide molecular-level insight into its cooperative assembly mechanism. The PhuZ family of tubulins is required to actively center the phage within infected host cells, facilitating efficient phage replication. Our reconstruction and derived model reveal the first example of a three-stranded tubulin filament. We show that the elongated C-terminal tail simultaneously stabilizes both longitudinal and lateral interactions, which in turn define filament architecture. Identified interaction surfaces are conserved within the PhuZ family, and their mutagenesis compromises polymerization in vitro and in vivo. Combining kinetic modeling of PhuZ filament assembly and structural data, we suggest a common filament structure and assembly mechanism for the PhuZ family of tubulins. The Structure and Assembly Mechanism of a Novel Three-Stranded Tubulin Filament that Centers Phage DNA.,Zehr EA, Kraemer JA, Erb ML, Coker JK, Montabana EA, Pogliano J, Agard DA Structure. 2014 Mar 11. pii: S0969-2126(14)00046-X. doi:, 10.1016/j.str.2014.02.006. PMID:24631461[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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