|
|
||||||||
1 Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Brisbane, Australia
2 Protagonist Propriety Limited, St. Lucia 4067, Queensland, Australia
(RECEIVED July 8, 2004; FINAL REVISION September 22, 2004; ACCEPTED September 23, 2004)
The presence and location of intramolecular disulphide bonds are a key determinant of the structure and function of proteins. Intramolecular disulphide bonds in proteins have previously been analyzed under the assumption that there is no clear relationship between disulphide arrangement and disulphide concentration. To investigate this, a set of sequence nonhomologous protein chains containing one or more intramolecular disulphide bonds was extracted from the Protein Data Bank, and the arrangements of the bonds, Protein Data Bank header, and Structural Characterization of Proteins fold were analyzed as a function of intramolecular disulphide bond concentration. Two populations of intramolecular disulphide bond-containing proteins were identified, with a naturally occurring partition at 25 residues per bond. These populations were named intramolecular disulphide bond-rich and -poor. Benefits of partitioning were illustrated by three results: (1) rich chains most frequently contained three disulphides, explaining the plateaux in extant disulphide frequency distributions; (2) a positive relationship between median chain length and the number of disulphides, only seen when the data were partitioned; and (3) the most common bonding pattern for chains with three disulphide bonds was based on the most common for two, only when the data were partitioned. The two populations had different headers, folds, bond arrangements, and chain lengths. Associations between IDSB concentration, IDSB bonding pattern, loop sizes, SCOP fold, and PDB header were also found. From this, we found that intramolecular disulphide bond-rich and -poor proteins follow different bonding rules, and must be considered separately to generate meaningful models of bond formation.
Keywords: disulphide; disulfide; nonhomologous; PDB; PDBSELECT; arrangement; pattern
Abbreviations: IDSB, intramolecular disulphide bond
PDB, Protein Data Bank SCOP, structural characterization of proteins database Con. A, concavalin-A
Article and publication are at http://www.proteinscience.org/cgi/doi/10.1110/ps.04923305.
Reprint requests to: Mark L. Smythe, Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Brisbane, Australia; e-mail: m.smythe{at}imb.uq.edu.au; fax: +61-7-3346-2101.
![]()
CiteULike
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
J. Song, Z. Yuan, H. Tan, T. Huber, and K. Burrage Predicting disulfide connectivity from protein sequence using multiple sequence feature vectors and secondary structure Bioinformatics, December 1, 2007; 23(23): 3147 - 3154. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |