Melvin's digital garden

Protein Flexibility

CREATED: 200701011018 Author: Anshul

** Motivation

  • binding, active site determination
  • structure determination
  • folding

** Given two conformations, determine rigid/flexible residues

  • PDB (protein database) provides ** temperature factor graph ** dihedral angles ** RMSD of sliding window ** data is noisy
  • Binary matrix

compute all fragment RMSD

apply statistical test

*** assume noise is gaussian *** noise level of theta *** rigid or flexible

binary matrix, 0 -> rigid, 1 -> flexible

  • Minimally flexible fragments (MFF) ** flexible fragment which does not contain flexible sub fragments
  • Flexibility of a residue = size of smallest MFF that contains the residue ** MMDB (molecular motion)

** Unknown flexibility

sample loop structures

** 6 non redundant dof -inverse kinematics-> dihedral angles ** motion in null space (local sampling)

find low engergy conformations

** use proxy energy functions *** approximation to actual energy function *** indicator to quickly reject bad samples

termination

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