Table 1.

PR⁻ MuLV composition and estimated protein dimensions

Protein	Size	Volume, Å3	Length, Å	Diameter, Å
Matrix (MA)	p15	19,186	≈40	≈25
Connector (pp12)	p12	15,349	≈25–60	≈18–28
Capsid (CA)	p30	38,372	≈100	≈20
Nucleocapsid (NC)	p10	12,791	≈25	≈25
Total length			≈200

For each of the mature MuLV Gag proteins, the predicted volume was calculated from the molecular weight (48), assuming a partial specific volume of 0.77 cm³/g. The dimensions of a cylinder of this volume were then calculated, using the lengths estimated from Fig. 4a to derive the diameters.