• Media type: E-Article
  • Title: Creating protein models from electron-density maps using particle-filtering methods
  • Contributor: DiMaio, Frank; Kondrashov, Dmitry A.; Bitto, Eduard; Soni, Ameet; Bingman, Craig A.; Phillips, George N.; Shavlik, Jude W.
  • Published: Oxford University Press (OUP), 2007
  • Published in: Bioinformatics, 23 (2007) 21, Seite 2851-2858
  • Language: English
  • DOI: 10.1093/bioinformatics/btm480
  • ISSN: 1367-4811; 1367-4803
  • Origination:
  • Footnote:
  • Description: AbstractMotivation: One bottleneck in high-throughput protein crystallography is interpreting an electron-density map, that is, fitting a molecular model to the 3D picture crystallography produces. Previously, we developed Acmi (Automatic Crystallographic Map Interpreter), an algorithm that uses a probabilistic model to infer an accurate protein backbone layout. Here, we use a sampling method known as particle filtering to produce a set of all-atom protein models. We use the output of Acmi to guide the particle filter's sampling, producing an accurate, physically feasible set of structures.Results: We test our algorithm on 10 poor-quality experimental density maps. We show that particle filtering produces accurate all-atom models, resulting in fewer chains, lower sidechain RMS error and reduced R factor, compared to simply placing the best-matching sidechains on Acmi's trace. We show that our approach produces a more accurate model than three leading methods—Textal, Resolve and ARP/WARP—in terms of main chain completeness, sidechain identification and crystallographic R factor.Availability: Source code and experimental density maps available at http://ftp.cs.wisc.edu/machine-learning/shavlik-group/programs/acmi/Contact:  dimaio@cs.wisc.edu
  • Access State: Open Access