Display technologies have been a cornerstone of protein engineering aiding in the development of novel proteins and improved functions. The leading display methodology for more than a decade has been phage display. Complimentary display techniques are also being developed, such as bacterial cell surface display. The key advantages of bacterial surface display are the ease of propagating bacteria, the ability to use quantitative screening techniques to rapidly isolate binding clones from large libraries, and the ability to characterize binding properties in situ. To advance bacterial display, we have engineered an outer membrane protein scaffold that allows for peptide fusions to be displayed at N- and C- termini exterior to the cell, a novel feature among outer membrane proteins of known structure. To achieve this, the monomeric outer membrane protein OmpX was circularly permuted by genetically fusing the native termini, previously oriented towards the periplasmic space, and opening the protein at the second extracellular loop, causing new termini to be located external to the cell. The circularly permutated variant allowed for the display of peptides fused to the N- or C- terminus, but the surface expression level of peptides was considerably decreased when compared to an insertion within a loop of the wild type OmpX. Directed evolution allowed for isolation of intragenic suppressor mutations that substantially increased display levels of control peptides. Surprisingly, these mutations mapped to the native C-terminus of the scaffold, a widely conserved region among beta-barrel outer membrane proteins. Further optimization of the linker sequence yielded expression capabilities equivalent to the non-permuted protein. Using this optimized display scaffold it is now possible to efficiently display peptides on both termini, and to monitor the expression level of peptide libraries by using an epitope tag on the opposing terminus or within an extracellular loop.