1CD3
PROCAPSID OF BACTERIOPHAGE PHIX174
Summary for 1CD3
Entry DOI | 10.2210/pdb1cd3/pdb |
Descriptor | PROTEIN (SCAFFOLDING PROTEIN GPD), PROTEIN (CAPSID PROTEIN GPF), PROTEIN (SPIKE PROTEIN GPG), ... (5 entities in total) |
Functional Keywords | complex (virus capsid proteins), bacteriophage, procapsid, scaffolding protein, chaperone, icosahedral virus, virus |
Biological source | Enterobacteria phage phiX174 More |
Total number of polymer chains | 7 |
Total formula weight | 149145.41 |
Authors | Rossmann, M.G.,Dokland, T. (deposition date: 1999-03-05, release date: 1999-04-14, Last modification date: 2024-04-03) |
Primary citation | Dokland, T.,Bernal, R.A.,Burch, A.,Pletnev, S.,Fane, B.A.,Rossmann, M.G. The role of scaffolding proteins in the assembly of the small, single-stranded DNA virus phiX174. J.Mol.Biol., 288:595-608, 1999 Cited by PubMed Abstract: An empty precursor particle called the procapsid is formed during assembly of the single-stranded DNA bacteriophage phiX174. Assembly of the phiX174 procapsid requires the presence of the two scaffolding proteins, D and B, which are structural components of the procapsid, but are not found in the mature virion. The X-ray crystallographic structure of a "closed" procapsid particle has been determined to 3.5 A resolution. This structure has an external scaffold made from 240 copies of protein D, 60 copies of the internally located B protein, and contains 60 copies of each of the viral structural proteins F and G, which comprise the shell and the 5-fold spikes, respectively. The F capsid protein has a similar conformation to that seen in the mature virion, and differs from the previously determined 25 A resolution electron microscopic reconstruction of the "open" procapsid, in which the F protein has a different conformation. The D scaffolding protein has a predominantly alpha-helical fold and displays remarkable conformational variability. We report here an improved and refined structure of the closed procapsid and describe in some detail the differences between the four independent D scaffolding proteins per icosahedral asymmetric unit, as well as their interaction with the F capsid protein. We re-analyze and correct the comparison of the closed procapsid with the previously determined cryo-electron microscopic image reconstruction of the open procapsid and discuss the major structural rearrangements that must occur during assembly. A model is proposed in which the D proteins direct the assembly process by sequential binding and conformational switching. PubMed: 10329166DOI: 10.1006/jmbi.1999.2699 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (3.5 Å) |
Structure validation
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