  We present the first Dyson-Schwinger calculation of the three-gluon vertex in
Landau-gauge QCD in which its full covariant structure is back-coupled
self-consistently. We truncate a Bose-symmetrized version of the DSE at the
level of one-loop diagrams, model the four-gluon vertex, and neglect terms that
contain non-primitively divergent n-point functions; the ghost-gluon vertex is
taken bare to good approximation. Fit functions for the ghost and gluon
propagators that interpolate between scaling and decoupling are presented. In
all aspects of our study Bose symmetry is manifest, from the truncation to the
basis decomposition and to the momentum invariants. We explore the uniform and
soft-collinear infrared limits and obtain the expected infrared exponents. The
presence of a zero crossing in the tree-level component of the vertex is
confirmed for both scaling- and decoupling-type scenarios. The zero crossing
appears at a scale ~1 GeV; however, its location might be sensitive to the
four-gluon vertex and missing components in the DSE.
