Native collagen has a two-bonded structure

An intermediate in the assembly of bacteriophage φX174 virions that sediments at 12 S and contains equimolar amounts of the capsid proteins coded by genes F and G was characterized. A functional B gene product seems necessary for the synthesis of this aggregate, that results from the joining of one 6 S particle (containing five molecules of G protein) to one 9 S particle (a pentamer of F protein). B protein is not found in the 12 S structure.