1. βα-Hairpin Clamps Brace βaβ Modules and Can Make Substantive Contributions to the Stability of TIM Barrel Proteins.
- Author
-
Xiaoyan Yang, Kathuria, Sagar V., Vadrevu, Ramakrishna, and Matthews, C. Robert
- Subjects
- *
MEDICAL research , *HYDROGEN bonding , *STABILITY (Mechanics) , *ALGORITHMS , *FOODBORNE diseases , *MOLECULAR association , *ESCHERICHIA coli , *CLAMPS (Engineering) - Abstract
Non-local hydrogen bonding interactions between main chain amide hydrogen atoms and polar side chain acceptors that bracket consecutive βα or αβ elements of secondary structure in αTS from E. coli, a TIM barrel protein, have previously been found to contribute 4-6 kcal mol-1 to the stability of the native conformation. Experimental analysis of similar βα-hairpin clamps in a homologous pair of TIM barrel proteins of low sequence identity, IGPS from S. solfataricus and E. coli, reveals that this dramatic enhancement of stability is not unique to αTS. A survey of 71 TIM barrel proteins demonstrates a 4-fold symmetry for the placement of βα-hairpin clamps, bracing the fundamental βαβ building block and defining its register in the (βα)8 motif. The preferred sequences and locations of βα-hairpin clamps will enhance structure prediction algorithms and provide a strategy for engineering stability in TIM barrel proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF