Novel integrative approach combines phenotypic and genotypic HIV-1 tropism analysis.

Phenotypically validated full-length gp160 sequences are examined with confidence.

Findings confirmed previously published tropism determinants in the V3 region.

New regions of interests include gp120-gp41 and gp41-gp41 interaction surfaces.

Potentially global mechanisms are implicated in modulating coreceptor specificity.