Fig. 4: Structure of Milano capsid.
From: Neck and capsid architecture of the robust Agrobacterium phage Milano
a Cryo-EM map of the Milano capsid shows that it consists of three building blocks: pentamer (orange), hexamer 1 (yellow) and hexamer 2 (green), each composed of the MCP (gp9). Icosahedral 2-fold, 3-fold and 5-fold symmetry are shown by filled black oval, triangle and pentagon, respectively. The local 2-fold symmetry is shown by an empty oval. b Structures of MCP (gp9), mCP (gp10), linking protein 1 (LP1, gp16) and linking protein 2 (LP2, gp128) are shown with N-to C-terminal colored blue-to-red. c Structure of pentamer, hexamer 1 and hexamer 2 differing in their decorating proteins. MCP, mCP, LP1 and LP2 are colored white, light pink, pink and yellow, respectively. Pentamer is decorated by five copies of LP2, hexamer1 is decorated by six copies of LP1 and hexamer 2 is decorated by five copies of LP2 and a single LP1. d Cryo-EM density corresponding to the β-sheet Ig-type domain of LP1, hanging out of hexamer 2 near the neck (Pink and indicated by red arrow). e Cryo-EM density corresponding to the β-sheet Ig-type domain of LP1 at pentamer and hexamer 2 hanging out of the capsid (Pink colored and indicated by red arrows). f Different conformations of P-domain, E-loop and N-arm of MCP (gp9) protomers in pentamer (orange) compared to those in hexamer 2 (grey).
