Construction and maintenance of randomized retroviral expression libraries for transmembrane protein engineering

In this study we used 454 sequencing to determine the composition, diversity and size of a randomized transmembrane protein expression library. Our results demonstrated that the library conformed well to its design and maintained a primarily hydrophobic amino acid composition. We also used our sequence data to estimate the size of the library. Finally, by sequencing the library after infection and recovery from mammalian cells, we were able to conclude that there are no major genetic bottlenecks in retroviral transduction of mammalian cells and recovery of library sequences by PCR.