title: The quaternary structure of the T4 gene product 20 oligomer.
abstract: Gene product 20 of phage T4, which occurs in the phage particle near the head-tail interface, has been purified under moderate denaturing conditions. Upon renaturation the protein forms ring-like structures, sedimenting at 19 S. The rings measure 17 nm in diameter and 7 nm in height. They are characterized by a central hole of 3 nm and have 12-fold rotational symmetry. The data are consistent with a dodecameric structure with a molecular weight of 0.8 X 10(6) daltons. The oligomers are able to associate into double rings and occasionally into higher regular aggregates. It is thought that this structure initiates the assembly of the prehead core which serves as a scaffold for the assembly of the shell. This, as well as other implications of the gp20 structure are discussed.
mesh_terms: D002213:Capsid; D006023:Glycoproteins; D046911:Macromolecular Substances; D008970:Molecular Weight; D011485:Protein Binding; D011487:Protein Conformation; D013604:T-Phages / Q000648:ultrastructure*; D014764:Viral Proteins
chemical_list: D006023:Glycoproteins; D046911:Macromolecular Substances; D014764:Viral Proteins