TABLE 1.

List of CA mutants and their assembly phenotypes in vitro and in vivo

Mutation(s)LocationaIn vitro cylinder formationbIn vivoc assembly
Presence of conical capsidParticle productionInfectivityd (n-fold less than wild type)
WT++++++1.0
Q7A/Q9ANTD β-hairpin++++++10 ± 3.5
R18A/N21ANTD helix 1Altered+ (multiple capsids)++0
R18ANTD helix 1AlteredNDNDND
N21ANTD helix 1++NDNDND
A22DNTD helix 1+++0
E28A/E29ANTD helix 1+++0
P38ANTD helix 2++++++33 ± 16
M39AeNTD helix 2NDNDND
A42DNTD helix 2++0
E45ANTD helix 2++++++29 ± 3.2
T54A/N57ANTD helix 3+++++80 ± 9
Q63A/Q67ANTD helix 4++++++34 ± 14
K70ANTD helix 4++ (few conical capsids)++21 ± 8
E75A/E76ANTD helix 4+++0
Δ87-97NTD CypA loopEnhancedNDNDND
R100A/S102ANTD helix 5+++0
T107A/T108ANTD helices 5 and 6+++0
T110A/Q112ANTD helix 6+++0
R132ANTD helix 7++++++6.2 ± 0.7
L136DNTD helix 7+++++91 ± 13
N139ANTD helix 7++++++1.2 ± 0.2
K158ACTD turn (MHR)Enhanced0
D163ACTD helix 8 (MHR)++++++15 ± 7
K170ACTD helix 8 (MHR)++++++0
W184ACTD helix 9+0
D197ACTD helix 10++0
K203ACTD helix 10+++++0
  • a Position in the secondary structure of HIV-1 CA (see Fig. 1).

  • b ++, similar to WT CA at all protein concentrations tested; +, cylinders were formed at 15 mg/ml but were severely attenuated at lower protein concentrations; −, severely attenuated at all protein concentrations tested; enhanced, significantly longer cylinders than WT CA; altered, assembled efficiently into spheres, cones, and short capped cylinders.

  • c In vivo data were previously reported in reference 53. ND, no data.

  • d Mutations that reduced infectivity >100-fold are listed as having an infectivity of 0.

  • e An alternative mutation in the same residue (M39D) blocked viral capsid assembly and infectivity (53).