A theoretical study to establish the relationship between the three-dimensional structure of triose-phosphate isomerase of Giardia duodenalis and point mutations in the respective gene

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Author(s)
Nolan, Matthew J
Hofmann, Andreas
Jex, Aaron R
Gasser, Robin B
Griffith University Author(s)
Year published
2010
Metadata
Show full item recordAbstract
Predicting how point mutations in genes alter the tertiary and quarternary structure of proteins is central to a number of areas of molecular biology and has implications in relation to the function and evolution of molecules. In the present study, we theoretically assessed the effects of 20 point mutations detected previously in a region of the triose-phosphate isomerase gene (tpi) of the protozoan Giardia duodenalis on the three-dimensional structure of the 'wild-type' protein (TPI). Amino acid substitutions arising from codon variations were mainly located at surface-accessible sites or in hydrophobic pockets of TPI. None ...
View more >Predicting how point mutations in genes alter the tertiary and quarternary structure of proteins is central to a number of areas of molecular biology and has implications in relation to the function and evolution of molecules. In the present study, we theoretically assessed the effects of 20 point mutations detected previously in a region of the triose-phosphate isomerase gene (tpi) of the protozoan Giardia duodenalis on the three-dimensional structure of the 'wild-type' protein (TPI). Amino acid substitutions arising from codon variations were mainly located at surface-accessible sites or in hydrophobic pockets of TPI. None of the substitutions was predicted to exert a significant change to the fold or functionality of the enzyme, with the exception of one alteration (Arg100). Almost all substitutions were either conservative or semi-conservative, and retained or even improved the expected stability of the fold. Overall, the findings provide support for the "neutral theory", which contends that evolution at the molecular level is not solely shaped by "Darwinian selection but also by random drift of selectively neutral or nearly neutral mutants".
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View more >Predicting how point mutations in genes alter the tertiary and quarternary structure of proteins is central to a number of areas of molecular biology and has implications in relation to the function and evolution of molecules. In the present study, we theoretically assessed the effects of 20 point mutations detected previously in a region of the triose-phosphate isomerase gene (tpi) of the protozoan Giardia duodenalis on the three-dimensional structure of the 'wild-type' protein (TPI). Amino acid substitutions arising from codon variations were mainly located at surface-accessible sites or in hydrophobic pockets of TPI. None of the substitutions was predicted to exert a significant change to the fold or functionality of the enzyme, with the exception of one alteration (Arg100). Almost all substitutions were either conservative or semi-conservative, and retained or even improved the expected stability of the fold. Overall, the findings provide support for the "neutral theory", which contends that evolution at the molecular level is not solely shaped by "Darwinian selection but also by random drift of selectively neutral or nearly neutral mutants".
View less >
Journal Title
Molecular and Cellular Probes
Volume
24
Issue
5
Copyright Statement
© 2010 Elsevier. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher. Please refer to the journal's website for access to the definitive, published version.
Subject
Medicinal and biomolecular chemistry
Biochemistry and cell biology
Structural biology (incl. macromolecular modelling)