Investigating Models of Protein Function and Allostery With a Widespread Mutational Analysis of a Light-Activated Protein

To investigate the relationship between a protein’s sequence and its biophysical properties, we studied the effects of more than 100 mutations in Avena sativa light-oxygen-voltage domain 2, a model protein of the Per-Arnt-Sim family. The A. sativa light–oxygen–voltage domain 2 undergoes a photocycle...

Full description

Saved in:
Bibliographic Details
Published in:Biophysical journal 2013-08, Vol.105 (4), p.1027-1036
Main Authors: Zayner, Josiah P., Antoniou, Chloe, French, Alexander R., Hause, Ronald J., Sosnick, Tobin R.
Format: Article
Language:English
Subjects:
Allosteric Regulation
Amino Acid Sequence
Avena
Avena sativa
chemistry
Conserved Sequence
Evolution, Molecular
Light
Models, Molecular
Molecular Sequence Data
Mutation
nuclear magnetic resonance spectroscopy
Plant Proteins - chemistry
Plant Proteins - genetics
Plant Proteins - metabolism
Protein Structure, Tertiary
Proteins and Nucleic Acids
Structure-Activity Relationship
ultraviolet-visible spectroscopy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:To investigate the relationship between a protein’s sequence and its biophysical properties, we studied the effects of more than 100 mutations in Avena sativa light-oxygen-voltage domain 2, a model protein of the Per-Arnt-Sim family. The A. sativa light–oxygen–voltage domain 2 undergoes a photocycle with a conformational change involving the unfolding of the terminal helices. Whereas selection studies typically search for winners in a large population and fail to characterize many sites, we characterized the biophysical consequences of mutations throughout the protein using NMR, circular dichroism, and ultraviolet/visible spectroscopy. Despite our intention to introduce highly disruptive substitutions, most had modest or no effect on function, and many could even be considered to be more photoactive. Substitutions at evolutionarily conserved sites can have minimal effect, whereas those at nonconserved positions can have large effects, contrary to the view that the effects of mutations, especially at conserved positions, are predictable. Using predictive models, we found that the effects of mutations on biophysical function and allostery reflect a complex mixture of multiple characteristics including location, character, electrostatics, and chemistry.
ISSN:0006-3495
1542-0086
DOI:10.1016/j.bpj.2013.07.010