Automated determination of interhelical angles for protein alpha helices from coordinate data Robert Fraser, James Stewart, Janice Glasgow Queen's University School of Computing, Kingston, ON
Protein Structure Contact Maps Helix Packing Models Proposed Method Results
The HUGE picture Sequence Structure Structure Function I’m working on a tiny bit of the first step
Protein Structure Different levels of structure We’re interested in alpha helices Used with permission from Petsko, G.A. and D. Ringe, Protein Structure and Function, 2004
Contact Maps Distance map represents full 3D structure Contact map is a binary version 10Ǻ threshold used here
Knobs and Holes Steric surface of the molecule
Two surfaces to a helix
Sign is important
Angle method if (d a × d b ) · (b 0 – a 0 ) > 0 then the top vector is rotated clockwise else the top vector is rotated counter-clockwise Clockwise negative sign
Comparison to observed values
Results 4.1° +/- 3.2° of observed data 3.6° +/- 1.9° after removing an outlier
Acknowledgements Kelly Fraser Janice Glasgow James Stewart Henk Meijer Mehdi Hedjazi Alan Ableson Eduardo Zuviria Tony Kuo
Thank you Questions?