21di: Difference between revisions
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==Cryo-EM reconstruction of the cyanophage Pam5 small terminase== | |||
<StructureSection load='21di' size='340' side='right'caption='[[21di]], [[Resolution|resolution]] 3.50Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[21di]] is a 9 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudanabaena_phage_Pam5 Pseudanabaena phage Pam5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=21DI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=21DI FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.5Å</td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=21di FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=21di OCA], [https://pdbe.org/21di PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=21di RCSB], [https://www.ebi.ac.uk/pdbsum/21di PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=21di ProSAT]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Efficient genome packaging is a critical step in the phage life cycle, directly influencing the viral maturation and infectivity. In tailed phages, this process is driven by a packaging motor composed of a portal protein and a terminase complex. The terminase complex usually consists of a large subunit (TerL) and a small subunit (TerS), which cooperate to recognize, cleave, and translocate genomic DNA into the capsid. However, due to the remarkable diversity and complexity of phage packaging systems, the molecular mechanisms governing TerS-mediated DNA recognition remain poorly understood. Here, we report the 3.51 A cryo-electron microscopy structure of the TerS from the short-tailed cyanophage Pam5, which infects the host Pseudanabaena mucicola Chao 1806. Pam5 TerS assembles into a nonameric ring with a radially symmetric spiral architecture. Biochemical assays show that Pam5 TerS recognizes the genomic DNA via a specific interaction between the N-terminal helix-turn-helix (HTH) domain of TerS and a 21-bp DNA sequence within the terS gene. In contrast, the TerS from another short-tailed cyanophage, Pam1, which infects the same host, binds to DNA in a sequence-independent manner. These findings reveal that cyanophages, even infecting the same host, could adopt two distinct DNA recognition strategies: HTH-mediated sequence-dependent or sequence-independent modes. This work provides structural and mechanistic insights into the diverse DNA-recognition strategies of TerS and advances our understanding of the evolutionary plasticity of viral genome packaging mechanisms. | |||
Structural and functional insights into the distinct DNA recognition mechanisms of the terminase small subunit TerS from cyanophages.,Dong DQ, Yang F, Du K, Xu K, Cheng WB, Chen Y, Zhou CZ, Jiang YL Acta Biochim Biophys Sin (Shanghai). 2026 Mar 20. doi: 10.3724/abbs.2026042. PMID:41865250<ref>PMID:41865250</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
<div class="pdbe-citations 21di" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Pseudanabaena phage Pam5]] | |||
[[Category: Dong DQ]] | |||
[[Category: Jiang YL]] | |||
[[Category: Zhou CZ]] | |||
