a, Formation of cyclopropane and vinyl chloride functional groups. b, Comparative sequence identities of the enzymes encoded by the two highly similar regions in the Cur and Jam pathways. The aligned DNA sequences are located at the boundaries of these two regions. c, Formation of 3-ACP3 in the Cur pathway, and hypothesized reactions for 4-ACP3, 5-ACP3 and 6-ACP3. The hypothetic chlorinated intermediates are shown along with the non-chlorinated ones. The β-branching carbon atoms are highlighted in red.