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Phylogenetic analysis of starch synthetic enzymes
Author(s) -
Kuhn Misty Lee,
Ballicora Miguel A.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb38-a
Subject(s) - phylogenetic tree , biology , endosymbiosis , gene , glycogen branching enzyme , starch , phylogenetics , starch synthase , biochemistry , glycogen , glycogen phosphorylase , genetics , computational biology , plastid , chloroplast , amylopectin , amylose
Glycogen and starch synthases catalyze the synthesis of glycogen in bacteria and starch in photosynthetic eukaryotes, respectively, using the donor molecule ADP‐glucose. These enzymes share a certain degree of similarity. In order to understand their evolution, a phylogenetic tree was constructed using the program TREE‐PUZZLE. The sequences used were obtained by an Iterated PSI‐Blast Search. A combination of automatic multiple sequence alignment and manual refinement based on homology modeling were used to align these sequences to the crystal structure of the Agrobacterium tumefaciens glycogen synthase. In addition, signatures (indels) were used to validate the tree branching pattern. The results of this tree revealed three main branches with multiple genes that existed for several glycogen and starch synthases. An interesting observation was that the cyanobacteria Crocosphaera watsonii had one gene on each of the three major branches of the unrooted tree. We concluded that there was an ancestral gene that duplicated in cyanobacteria multiple times before it was inherited by plants in an endosymbiotic process. This is the opposite of what we observed with ADP‐glucose pyrophosphorylase, the first enzyme of the pathway, in which the major duplications occurred after endosymbiosis. This material is based upon work supported by the National Science Foundation under Grant No. MCB 0615982.