Unless otherwise noted, all chemicals used in this study were obtained from Sigma-Aldrich, Carbosynth, or GE Healthcare Biosciences. The bacterial growth medium, agarose and isopropyl-β-d-thiogalactopyranoside (IPTG) were purchased from Research Products International (RPI). Escherichia coli strain BL21-Gold (DE3) and the restriction enzyme DpnI were obtained from New England Biolabs. PfuTurbo DNA polymerase was purchased from Agilent. DNA sequencing was conducted by Eton Biosciences Inc. GDP-d-glycero-α-d-manno-heptose (1) was enzymatically synthesized and purified as described previously (9 (link)).