9iny
From Proteopedia
Structure of bacteriophage T5 tail tube
Structural highlights
FunctionTUBE_BPT5 Polymerizes to make up the central tail tube that is surrounded by the tail sheath protein (TSP). Tail tube protein polymerization takes place around the tape measure protein (TMP) and is probably directed by chaperone proteins. The tail is a stack of 40 trimeric rings of the TTP. Upon binding to host cell, the tail sheath contracts and the tail tube penetrates the host envelope. The tail tube is involved in viral genome delivery during ejection.[1] [2] Publication Abstract from PubMedT5 is a siphophage that has been extensively studied by structural and biochemical methods. However, the complete in situ structures of T5 before and after DNA ejection remain unknown. In this study, we used cryo-electron microscopy (cryo-EM) to determine the structures of mature T5 (a laboratory-adapted, fiberless T5 mutant) and urea-treated empty T5 (lacking the tip complex) at near-atomic resolutions. Atomic models of the head, connector complex, tail tube, and tail tip were built for mature T5, and atomic models of the connector complex, comprising the portal protein pb7, adaptor protein p144, and tail terminator protein p142, were built for urea-treated empty T5. Our findings revealed that the aforementioned proteins did not undergo global conformational changes before and after DNA ejection, indicating that these structural features were conserved among most myophages and siphophages. The present study elucidates the underlying mechanisms of siphophage infection and DNA ejection. Structures of Mature and Urea-Treated Empty Bacteriophage T5: Insights into Siphophage Infection and DNA Ejection.,Peng Y, Tang H, Xiao H, Chen W, Song J, Zheng J, Liu H Int J Mol Sci. 2024 Aug 3;25(15):8479. doi: 10.3390/ijms25158479. PMID:39126049[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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