Figure 1.

pnp locus in recombinant E. coli strains and growth of the hPNPase expressing strain. (A) The structure of the pnp locus in the E. coli strains listed on the left is shown. Empty blue box, pnp ORF; filled blue box, PNPT1_Ec ORF; dashed lines, 5′- and 3′-UTR of the E. coli pnp gene; s, FRT scar⁴¹; h, His-tag. On the right, PNPase variant expressed by each strain. Ec, E. coli PNPase; Hs, human PNPase. (B) Growth in LD broth. Cultures (N = 3) were grown at 37 °C with shaking in LD measuring the optical density at intervals. The symbols indicated average with standard deviation (StD). C-1a (pnp⁺), black symbols; C-5691 (Δpnp), empty symbols; C-6001 (PNPT1_Ec), grey symbols.