FIG 3.

Classification of HIV-1 particles observed by cryo-ET. (A to D) Tomographic central slices of representative HIV-1 virions classified according to core morphology (conical or nonconical) and the presence or absence of an eccentric condensate (white arrows). Eccentric condensates appear denser than the material lying between the core and the envelope in particles that lack an eccentric condensate. The cores of virions that have an eccentric condensate are relatively empty (e.g., panel B). Bar, 50 nm. (E) Percentages of HIV-1 virions classified according to their core morphology (conical, nonconical, or no core) and presence or absence of an eccentric condensate. The majority species for each sample is indicated by values in bold. According to the chi-square test, significant differences with P values of <0.00001 were found for comparisons between WT and BIB-2 and between WT and the V165A mutant. The difference between WT and BI-D had a P value of 0.013, whereas the differences between the V165A mutant and BI-D or BIB-II were not significant, with P values of >0.26. The chi-square test was used to test for equal distribution of compartmentalized data but should not be used if more of 20% of the bins contain fewer than 5 counts. Therefore, immature virions were not taken into account and virions with no cores were considered a single category, independent of the presence or absence of an eccentric condensate.