3GQ7: Crystal Structure of the Bacteriophage Phi29 Gene Product 12 N-terminal Fragment

The tailed bacteriophage phi29 has 12 "appendages" (gene product 12, gp12) attached to its neck region that participate in host cell recognition and entry. In the cell, monomeric gp12 undergoes proteolytic processing that releases the C-terminal domain during assembly into trimers. We report here crystal structures of the protein before and after catalytic processing and show that the C-terminal domain of gp12 is an "autochaperone" that aids trimerization. We also show that autocleavage of the C-terminal domain is a posttrimerization event that is followed by a unique ATP-dependent release. The posttranslationally modified N-terminal part has three domains that function to attach the appendages to the phage, digest the cell wall teichoic acids, and bind irreversibly to the host, respectively. Structural and sequence comparisons suggest that some eukaryotic and bacterial viruses as well as bacterial adhesins might have a similar maturation mechanism as is performed by phi29 gp12 for Bacillus subtilis.
PDB ID: 3GQ7Download
MMDB ID: 72924
PDB Deposition Date: 2009/3/24
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.05  Å
Source Organism:
Similar Structures:
Biological Unit for 3GQ7: trimeric; determined by author and by software (PISA)
Molecular Components in 3GQ7
Label Count Molecule
Proteins (3 molecules)
Preneck Appendage Protein
Molecule annotation
Chemicals (12 molecules)
* Click molecule labels to explore molecular sequence information.

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