Bioinformatics, Vol 14, 857-865, Copyright © 1998 by Oxford University Press
CT Zhang and R Zhang
MOTIVATION: With the enlargement of protein structure databases, it is
hoped that a method to classify proteins automatically will be developed.
Although the classification criterion proposed by Nakashima et al. ( J.
Biochem., 1986, 99, 153-162) was widely used in the literature, it leads to
some inconsistencies with the classification databases currently available
in the class assignment of protein structures. To improve their work, a new
classification criterion is proposed relying on statistical analysis of the
secondary structure contents of more than 200 proteins with well-known
structural classes. The Fisher linear discriminant algorithm is used to
derive the new classification criterion. RESULTS: Three cross-validation
tests are performed to evaluate the new criterion. In the jackknife test,
of the 210 proteins used to derive the criterion, 206 are correctly
classified with an accuracy of 98.10%. Of the 16 proteins of purely
intermediate structure (i.e. structures lying near borderlines between two
classes) in the first test set, 15 are correctly classified with an
accuracy of 93.75%. For the second test set which consists of 200 proteins
selected randomly from SCOP, a testing accuracy of 94.00% is obtained. For
comparison, the criterion of Nakashima et al. is also used to classify the
210, 16 and 200 proteins, respectively. Consequently, accuracies of 94.76%,
62.50% and 91.50% are obtained, respectively. On average, the accuracy of
the new classification criterion is 4% higher than that of Nakashima et al.
AVAILABILITY: The program is available on request from the first author.
CONTACT: ctzhang@tju.edu.cn
ARTICLES
A new criterion to classify globular proteins based on their secondary structure contents
Department of Physics, Tianjin University, Tianjin 300072, China and Department of Epidemiology and Biostatistics, Tianjin Cancer Institute and Hospital, Tianjin 300060, China. ctzhang@tju.edu.cn
![]()
CiteULike
Connotea
Del.icio.us What's this?