Title
A mathematical framework for protein structure comparison.
Abstract
Comparison of protein structures is important for revealing the evolutionary relationship among proteins, predicting protein functions and predicting protein structures. Many methods have been developed in the past to align two or multiple protein structures. Despite the importance of this problem, rigorous mathematical or statistical frameworks have seldom been pursued for general protein structure comparison. One notable issue in this field is that with many different distances used to measure the similarity between protein structures, none of them are proper distances when protein structures of different sequences are compared. Statistical approaches based on those non-proper distances or similarity scores as random variables are thus not mathematically rigorous. In this work, we develop a mathematical framework for protein structure comparison by treating protein structures as three-dimensional curves. Using an elastic Riemannian metric on spaces of curves, geodesic distance, a proper distance on spaces of curves, can be computed for any two protein structures. In this framework, protein structures can be treated as random variables on the shape manifold, and means and covariance can be computed for populations of protein structures. Furthermore, these moments can be used to build Gaussian-type probability distributions of protein structures for use in hypothesis testing. The covariance of a population of protein structures can reveal the population-specific variations and be helpful in improving structure classification. With curves representing protein structures, the matching is performed using elastic shape analysis of curves, which can effectively model conformational changes and insertions/deletions. We show that our method performs comparably with commonly used methods in protein structure classification on a large manually annotated data set.
Year
DOI
Venue
2011
10.1371/journal.pcbi.1001075
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
hypothesis test,shape analysis,random variable,geodesic distance,protein structure,three dimensional,probability distribution
Global distance test,Population,Random variable,Biology,Probability distribution,Bioinformatics,Statistical hypothesis testing,Covariance,Shape analysis (digital geometry),Protein structure
Journal
Volume
Issue
ISSN
7
2
1553-734X
Citations 
PageRank 
References 
10
0.63
24
Authors
3
Name
Order
Citations
PageRank
Wei Liu1100.63
Anuj Srivastava22853199.47
Jinfeng Zhang38610.11