2FTE: Bacteriophage Hk97 Expansion Intermediate Iv

Maturation of the bacteriophage HK97 capsid from a precursor (Prohead II) to the mature state (Head II) involves a 60 A radial expansion. The mature particle is formed by 420 copies of the major capsid protein organized on a T = 7 laevo lattice with each subunit covalently crosslinked to two neighbors. Well-characterized pH 4 expansion intermediates make HK97 valuable for investigating quaternary structural dynamics. Here, we use X-ray crystallography and cryo-EM to demonstrate that in the final transition in maturation (requiring neutral pH), pentons in Expansion Intermediate IV (EI-IV) reversibly sample 14 A translations and 6 degrees rotations relative to a fixed hexon lattice. The limit of this trajectory corresponds to the Head II conformation that is secured at this extent only by the formation of the final class of covalent crosslinks. Mutants that cannot crosslink or EI-IV particles that have been rendered incapable of forming the final crosslink remain in the EI-IV state.
PDB ID: 2FTEDownload
MMDB ID: 37815
PDB Deposition Date: 2006/1/24
Updated in MMDB: 2006/12
Experimental Method:
electron microscopy
Source Organism:
Similar Structures:
Biological Unit for 2FTE: 420-meric
Molecular Components in 2FTE
Label Count Molecule
Proteins (420 molecules)
Major Capsid Protein(Gene symbol: HK97p05)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB