Computational design with supersecondary structures as building blocks has proven effective in the construction of new proteins with controlled geometries. So far, this approach has primarily exploited amplification, effectively harnessing the internal folding propensity of self-compatible fragments to achieve sufficient enthalpy for folding. Here we exploit an interface-driven strategy to depart from the repeat design realm, constructing an asymmetric, globular domain from heterologous supersecondary structures. We report the successful design of a dRP lyase domain fold, which agrees with the experimental NMR structure at atomic accuracy (backbone RMSD of 0.94 angstrom). Our results show that the residual folding information within conserved fragments, combined with efficient interface-directed sampling, can effectively yield globular proteins with novel sequences and biophysical properties.