THE PLANT GENOME: AN EVOLUTIONARY VIEW ON STRUCTURE AND FUNCTION
Genome-level and biochemical diversity of the acyl-activating enzyme superfamily in plants
Article first published online: 28 MAR 2011
The Plant Journal © 2011 Blackwell Publishing Ltd. No claim to original US government works
The Plant Journal
Special Issue: The Plant Genome: An Evolutionary View on Structure and Function
Volume 66, Issue 1, pages 143–160, April 2011
How to Cite
Shockey, J. and Browse, J. (2011), Genome-level and biochemical diversity of the acyl-activating enzyme superfamily in plants. The Plant Journal, 66: 143–160. doi: 10.1111/j.1365-313X.2011.04512.x
- Issue published online: 28 MAR 2011
- Article first published online: 28 MAR 2011
- Received 15 October 2010; revised 19 January 2011; accepted 21 January 2011.
- acyl-activating enzyme;
- Coenzyme A ligase;
- acyl-Coenzyme A synthetase;
In higher plants, the superfamily of carboxyl-CoA ligases and related proteins, collectively called acyl activating enzymes (AAEs), has evolved to provide enzymes for many pathways of primary and secondary metabolism and for the conjugation of hormones to amino acids. Across the superfamily there is only limited sequence similarity, but a series of highly conserved motifs, including the AMP-binding domain, make it easy to identify members. These conserved motifs are best understood in terms of the unique domain-rotation architecture that allows AAE enzymes to catalyze the two distinct steps of the CoA ligase reaction. Arabidopsis AAE sequences were used to identify the AAE gene families in the sequenced genomes of green algae, mosses, and trees; the size of the respective families increased with increasing degree of organismal cellular complexity, size, and generation time. Large-scale genome duplications and small-scale tandem gene duplications have contributed to AAE gene family complexity to differing extents in each of the multicellular species analyzed. Gene duplication and evolution of novel functions in Arabidopsis appears to have occurred rapidly, because acquisition of new substrate specificity is relatively easy in this class of proteins. Convergent evolution has also occurred between members of distantly related clades. These features of the AAE superfamily make it difficult to use homology searches and other genomics tools to predict enzyme function.