4DIV: The Structure Of A 1.8 Mda Viral Genome Injection Device Suggests Alternative Infection Mechanisms

Phages of the Caudovirales order possess a tail that recognizes the host and ensures genome delivery upon infection. The X-ray structure of the approximately 1.8 MDa host adsorption device (baseplate) from the lactococcal phage TP901-1 shows that the receptor-binding proteins are pointing in the direction of the host, suggesting that this organelle is in a conformation ready for host adhesion. This result is in marked contrast with the lactococcal phage p2 situation, whose baseplate is known to undergo huge conformational changes in the presence of Ca(2+) to reach its active state. In vivo infection experiments confirmed these structural observations by demonstrating that Ca(2+) ions are required for host adhesion among p2-like phages (936-species) but have no influence on TP901-1-like phages (P335-species). These data suggest that these two families rely on diverse adhesion strategies which may lead to different signaling for genome release.
MMDB ID: 100416
PDB Deposition Date: 2012/2/1
Updated in MMDB: 2012/08
Experimental Method:
x-ray diffraction
Resolution: 3.8  Å
Source Organism:
Lactococcus phage TP901-1
Similar Structures:
Merged PDB IDs:4DIV 4DIW
Asymmetric Unit for 4DIV: 78-meric

Citing MMDB