Modeling and Computational Biology
Cannon, Nathaniel , Cardwell, Jonathan , McClellan, David , Coleman, Craig .
Evolutionary Relationship and Directional Selection of Seed Storage Proteins.
Legumins (11S globulins) and vicilins (7S globulins) are seed storage proteins used during seed germination in angiosperms. There is a significant amount of structural and sequence similarity between these two protein families. Germins and germin-like proteins (GLPs) are also similar in tertiary structure to the subunits of 11S and 7S globulins, all of which consist of two cupin domains. Studies have hinted at the evolutionary relationship between these proteins, indicating that germins may be highly similar to a protein ancestral to all three groups. Our more extensive analyses span the three groups and support the notion of a germin-like ancestor to modern storage proteins. Putative germins and GLPs are found scattered throughout the genomes of most plants. Homologues were identified using Hidden-Markov Models based on protein family (pFam) domain motifs. Germins and GLPs perform a wide variety of functions, such as bacterial resistance, osmotic regulation, and apoptosis. As such it is expected that there has been significant gene duplication events with subsequent functional differentiation. Germin homologues do not clade by species in phylogenies; rather, they group together based on what appear to be germin sub-family structure. This suggests ancient divisions in the germin family may have led to different evolutionary pathways for 11S and 7S globulin families. If gene duplication and oligomerization are the mechanisms of evolution for 11S and 7S globulins then structural and sequence comparison may reveal different patterns of selection since divergence from germins. We identified sites in 11S and 7S globulins under selection and found that they correlate with structural and functional differentiation in 11S and 7S globulin proteins.
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1 - Brigham Young University, Plant and Animal Sciences, 275 WidB, Provo, UT, 84602-5253, United States
2 - Brigham Young University, Plant and Animal Sciences
3 - Brigham Young University, Integrative Biology
seed storage protein
gene family evolution.
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM