Figure 1. Structure of NTUH-K2044 CPS trisaccharide and summary of our work.

A, The upper scheme shows the annotated cps cluster and its upstream and downstream genes reported previously. In the middle scheme, the blue bar indicates the CPS gene cluster re-delimited in this work, from gnd (kp3701) to galF (kp3726). In the lower scheme, the grey bar indicates the suppressed gene region [from wbaP (kp3705) to fbaB (kp3767)] in ΔwcaI, ΔwcaH, and Δatf deletion strains identified in this work. (The color codes used in the cps locus represent the following genes: orange - biosynthesis of glucose in the trisaccharide formation; dark green - biosynthesis of fucose; purple - decoration of acetyl moiety; pink - biosynthesis of glucuronic acid; light green - decoration of pyruvyl moiety; dark blue – regulation of the cps locus and assembly of the long train CPS.) B, Re-determined CPS trisaccharide structure.