2JES: Portal Protein (gp6) From Bacteriophage Spp1

Tailed bacteriophages and herpesviruses load their capsids with DNA through a tunnel formed by the portal protein assembly. Here we describe the X-ray structure of the bacteriophage SPP1 portal protein in its isolated 13-subunit form and the pseudoatomic structure of a 12-subunit assembly. The first defines the DNA-interacting segments (tunnel loops) that pack tightly against each other forming the most constricted part of the tunnel; the second shows that the functional dodecameric state must induce variability in the loop positions. Structural observations together with geometrical constraints dictate that in the portal-DNA complex, the loops form an undulating belt that fits and tightly embraces the helical DNA, suggesting that DNA translocation is accompanied by a 'mexican wave' of positional and conformational changes propagating sequentially along this belt.
PDB ID: 2JESDownload
MMDB ID: 45121
PDB Deposition Date: 2007/1/21
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 3.4  Å
Source Organism:
Similar Structures:
Biological Unit for 2JES: 26-meric; determined by author and by software (PISA)
Molecular Components in 2JES
Label Count Molecule
Proteins (26 molecules)
Portal Protein(Gene symbol: SPP1p010)
Molecule annotation
Unidentified Fragment of Portal Protein
Molecule annotation
Chemicals (26 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB