7zhj
From Proteopedia
Tail tip of siphophage T5 : tip proteins
Structural highlights
FunctionTMP_BPT5 Functions as a tape measure protein that serves as a base for tail tube protein polymerization and acts as a template for tail length determination (PubMed:18348984, PubMed:36961893). Fills the tail tube with its long coiled-coil domain and is expelled during the conformation changes that follow T5 binding to host FhuA (PubMed:18348984, PubMed:36961893). Forms a channel through the outer-membrane after binding of the receptor binding protein pb5 with the host receptor FhuA (PubMed:36961893).[1] [2] Displays an exolysin activity that is probably involved in the fusion with the host membrane and in the host peptidoglycan digestion necessary for viral DNA entry into the host cell.[3] Publication Abstract from PubMedMost bacteriophages present a tail allowing host recognition, cell wall perforation, and viral DNA channeling from the capsid to the infected bacterium cytoplasm. The majority of tailed phages bear a long flexible tail (Siphoviridae) at the tip of which receptor binding proteins (RBPs) specifically interact with their host, triggering infection. In siphophage T5, the unique RBP is located at the extremity of a central fiber. We present the structures of T5 tail tip, determined by cryo-electron microscopy before and after interaction with its E. coli receptor, FhuA, reconstituted into nanodisc. These structures bring out the important conformational changes undergone by T5 tail tip upon infection, which include bending of T5 central fiber on the side of the tail tip, tail anchoring to the membrane, tail tube opening, and formation of a transmembrane channel. The data allow to detail the first steps of an otherwise undescribed infection mechanism. Structural basis of bacteriophage T5 infection trigger and E. coli cell wall perforation.,Linares R, Arnaud CA, Effantin G, Darnault C, Epalle NH, Boeri Erba E, Schoehn G, Breyton C Sci Adv. 2023 Mar 24;9(12):eade9674. doi: 10.1126/sciadv.ade9674. Epub 2023 Mar , 24. PMID:36961893[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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