Figure 8.

Phylogenetic Analysis of Cyanobacterial, Bacterial, and Archaeplastidal Glycogen DBEs.

Starch DBEs in Chloroplastida play an important role in polysaccharide synthesis and in starch degradation. The maximum likelihood phylogeny of these enzymes shows that the three isoforms of isoamylase in Chloroplastida (green text) and the DBE found in Glaucophyta (blue text) and Rhodophyta (red text) do not share the same phylogenetic origin as the cyanobacterial GlgX (magenta text), particularly for Cyanobacterium sp CLg1. Rather, GlgX enzymes in Archaeplastida are sister to Chlamydiae (orange text; bootstrap support value is 90%), strongly suggesting a chlamydial origin of the gene in this eukaryotic supergroup (Ball et al., 2013). Alignments are given in Supplemental Data Set 1 online.