Source code for prody.proteins.functions

# -*- coding: utf-8 -*-
"""This module defines miscellaneous functions dealing with protein data."""

import numpy as np

from prody.atomic import Atomic, Atom, AtomGroup, Selection, HierView
from prody.utilities import openFile, showFigure
from prody import SETTINGS

__all__ = ['view3D','showProtein', 'writePQR', ]


[docs]def writePQR(filename, atoms): """Write *atoms* in PQR format to a file with name *filename*. Only current coordinate set is written. Returns *filename* upon success. If *filename* ends with :file:`.gz`, a compressed file will be written.""" if not isinstance(atoms, Atomic): raise TypeError('atoms does not have a valid type') if isinstance(atoms, Atom): atoms = Selection(atoms.getAtomGroup(), [atoms.getIndex()], atoms.getACSIndex(), 'index ' + str(atoms.getIndex())) stream = openFile(filename, 'w') n_atoms = atoms.numAtoms() atomnames = atoms.getNames() if atomnames is None: raise RuntimeError('atom names are not set') for i, an in enumerate(atomnames): lenan = len(an) if lenan < 4: atomnames[i] = ' ' + an elif lenan > 4: atomnames[i] = an[:4] s_or_u = np.array(['a']).dtype.char resnames = atoms._getResnames() if resnames is None: resnames = ['UNK'] * n_atoms resnums = atoms._getResnums() if resnums is None: resnums = np.ones(n_atoms, int) chainids = atoms._getChids() if chainids is None: chainids = np.zeros(n_atoms, s_or_u + '1') charges = atoms._getCharges() if charges is None: charges = np.zeros(n_atoms, float) radii = atoms._getRadii() if radii is None: radii = np.zeros(n_atoms, float) icodes = atoms._getIcodes() if icodes is None: icodes = np.zeros(n_atoms, s_or_u + '1') hetero = ['ATOM'] * n_atoms heteroflags = atoms._getFlags('hetatm') if heteroflags is None: heteroflags = atoms._getFlags('hetero') if heteroflags is not None: hetero = np.array(hetero, s_or_u + '6') hetero[heteroflags] = 'HETATM' altlocs = atoms._getAltlocs() if altlocs is None: altlocs = np.zeros(n_atoms, s_or_u + '1') format = ('{0:6s}{1:5d} {2:4s}{3:1s}' + '{4:4s}{5:1s}{6:4d}{7:1s} ' + '{8:8.3f}{9:8.3f}{10:8.3f}' + '{11:8.4f}{12:7.4f}\n').format coords = atoms._getCoords() write = stream.write for i, xyz in enumerate(coords): write(format(hetero[i], i+1, atomnames[i], altlocs[i], resnames[i], chainids[i], int(resnums[i]), icodes[i], xyz[0], xyz[1], xyz[2], charges[i], radii[i])) write('TER\nEND') stream.close() return filename
[docs]def view3D(*alist, **kwargs): """Return a py3Dmol view instance for interactive visualization in Jupyter notebooks. Available arguments are: width, height (of the viewer), backgroundColor, zoomTo (a py3Dmol selection to center around), and style, which is a py3Dmol style object that will be applied to all atoms in the scene. More complex styling can be achieved by manipulating the view object directly. The default style is to show the protein in a rainbow cartoon and hetero atoms in sticks/spheres. GNM/ANM Coloring An array of fluctuation values can be provided with the flucts kwarg for visualization of GNM/ANM calculations. The array is assumed to correpond to a calpha selection of the provided protein. The default color will be set to a RWB color scheme on a per-residue basis. If the fluctuation vector contains negative values, the midpoint (white) will be at zero. Otherwise the midpoint is the mean. An array of displacement vectors can be provided with the vecs kwarg. The animation of these motions can be controlled with frames (number of frames to animate over), amplitude (scaling factor), and animate (3Dmol.js animate options). """ import StringIO, py3Dmol from pdbfile import writePDBStream pdb = StringIO.StringIO() for atoms in alist: writePDBStream(pdb, atoms) width = kwargs.get('width',400) height = kwargs.get('height',400) view = py3Dmol.view(width=width,height=height,js=kwargs.get('js','http://3dmol.csb.pitt.edu/build/3Dmol-min.js')) #case insensitive kwargs.. bgcolor = kwargs['backgroundcolor'] if 'backgroundcolor' in kwargs else kwargs.get('backgroundColor','white') view.setBackgroundColor(bgcolor) view.addModels(pdb.getvalue(),'pdb') view.setStyle({'cartoon': {'color':'spectrum'}}) view.setStyle({'hetflag': True}, {'stick':{}}) view.setStyle({'bonds': 0}, {'sphere':{'radius': 0.5}}) if 'flucts' in kwargs: garr = kwargs['flucts'] #note we are only getting info from last set of atoms.. if atoms.calpha.numAtoms() != len(garr): raise RuntimeError("Atom count mismatch: {} vs {}. flucts styling assume a calpha selection.".format(atoms.calpha.numAtoms(), len(garr))) else: #construct map from residue to flucts property propmap = [] for (i,a) in enumerate(atoms.calpha): propmap.append({'chain': a.getChid(), 'resi':a.getResnum(), 'props': {'flucts': garr[i] } }) #set the atom property #TODO: implement something more efficient on the 3Dmol.js side (this is O(n*m)!) view.mapAtomProperties(propmap) #color by property using gradient extreme = np.abs(garr).max() lo = -extreme if garr.min() < 0 else 0 mid = np.mean(garr) if garr.min() >= 0 else 0 view.setColorByProperty({}, 'flucts', 'rwb', [extreme,lo,mid]) view.setStyle({'cartoon':{'style':'trace'}}) if 'vecs' in kwargs: aarr = kwargs['vecs'] #has xyz coordinates #note we are only getting info from last set of atoms.. if atoms.calpha.numAtoms()*3 != len(aarr): raise RuntimeError("Atom count mismatch: {} vs {}. vecs animation assume a calpha selection.".format(atoms.calpha.numAtoms(), len(aarr)/3)) else: #construct map from residue to anm property and dx,dy,dz vectors propmap = [] for (i,a) in enumerate(atoms.calpha): propmap.append({'chain': a.getChid(), 'resi':a.getResnum(), 'props': {'dy': aarr[3*i+1], 'dz': aarr[3*i+2] } }); #set the atom property #TODO: implement something more efficient on the 3Dmol.js side (this is O(n*m)!) view.mapAtomProperties(propmap) #create vibrations frames = kwargs.get('frames',10) amplitude = kwargs.get('amplitude',100) view.vibrate(frames, amplitude) animate = kwargs.get('animate',{'loop':'rock'}) view.animate(animate) if 'style' in kwargs: # this is never a list view.setStyle({},kwargs['style']) if 'styles' in kwargs: #allow simpler forms - convert them into a list styles = kwargs['styles'] if type(styles) == dict: styles = ({},styles) if type(styles) == tuple: styles = [styles] for (sel, style) in styles: view.setStyle(sel, style) zoomto = kwargs['zoomto'] if 'zoomto' in kwargs else kwargs.get('zoomTo',{}) view.zoomTo(zoomto) return view
[docs]def showProtein(*atoms, **kwargs): """Show protein representation using :meth:`~mpl_toolkits.mplot3d.Axes3D`. This function is designed for generating a quick view of the contents of a :class:`~.AtomGroup` or :class:`~.Selection`. Protein atoms matching ``"calpha"`` selection are displayed using solid lines by picking a random and unique color per chain. Line with can be adjusted using *lw* argument, e.g. ``lw=12``. Default width is 4. Chain colors can be overwritten using chain identifier as in ``A='green'``. Water molecule oxygen atoms are represented by red colored circles. Color can be changed using *water* keyword argument, e.g. ``water='aqua'``. Water marker and size can be changed using *wmarker* and *wsize* keywords, defaults values are ``wmarker='.', wsize=6``. Hetero atoms matching ``"hetero and noh"`` selection are represented by circles and unique colors are picked at random on a per residue basis. Colors can be customized using residue name as in ``NAH='purple'``. Note that this will color all distinct residues with the same name in the same color. Hetero atom marker and size can be changed using *hmarker* and *hsize* keywords, default values are ``hmarker='o', hsize=6``. ProDy will set the size of axis so the representation is not distorted when the shape of figure window is close to a square. Colors are picked at random, except for water oxygens which will always be colored red. *** Interactive 3D Rendering in Jupyter Notebook *** If py3Dmol has been imported then it will be used instead to display an interactive viewer. See :func:`view3D` """ alist = atoms for atoms in alist: if not isinstance(atoms, Atomic): raise TypeError('atoms must be an Atomic instance') import sys if 'py3Dmol' in sys.modules: return view3D(*alist, **kwargs).show() else: import matplotlib.pyplot as plt from mpl_toolkits.mplot3d import Axes3D cf = plt.gcf() show = None for child in cf.get_children(): if isinstance(child, Axes3D): show = child break if show is None: show = Axes3D(cf) from matplotlib import colors cnames = dict(colors.cnames) wcolor = kwargs.get('water', 'red').lower() avoid = np.array(colors.hex2color(cnames.pop(wcolor, cnames.pop('red')))) for cn, val in cnames.copy().items(): # PY3K: OK clr = np.array(colors.hex2color(val)) if clr.sum() > 2.4: cnames.pop(cn) elif np.abs(avoid - clr).sum() <= 0.6: cnames.pop(cn) cnames = list(cnames) import random random.shuffle(cnames) min_ = list() max_ = list() for atoms in alist: if isinstance(atoms, AtomGroup): title = atoms.getTitle() else: title = atoms.getAtomGroup().getTitle() calpha = atoms.select('calpha') if calpha: from prody.dynamics.mode import Mode gnmmode = kwargs.get('mode', None) if gnmmode is None: for ch in HierView(calpha, chain=True): xyz = ch._getCoords() chid = ch.getChid() show.plot(xyz[:, 0], xyz[:, 1], xyz[:, 2], label=title + '_' + chid, color=kwargs.get(chid, cnames.pop()).lower(), lw=kwargs.get('lw', 4)) else: xyz = calpha._getCoords() chids = calpha.getChids() arr = [] if isinstance(gnmmode, Mode): arr = gnmmode.getArray() else: arr = gnmmode if len(arr) != len(calpha): raise RuntimeError('The number of residues should be equal to the size of the GNM mode.') rbody = [] last_sign = np.sign(arr[0]) last_chid = chids[0] rcolor = ['red', 'red', 'blue'] n = 1 for i,a in enumerate(arr): s = np.sign(a) ch = chids[i] if s == 0: s = last_sign if last_sign != s or i == len(arr)-1 or last_chid != ch: if last_chid == ch: rbody.append(i) show.plot(xyz[rbody, 0], xyz[rbody, 1], xyz[rbody, 2], label=title + '_regid%d'%n, color=rcolor[int(last_sign+1)], lw=kwargs.get('lw', 4)) rbody = [] n += 1 last_sign = s last_chid = ch rbody.append(i) water = atoms.select('water and noh') if water: xyz = atoms.select('water')._getCoords() show.plot(xyz[:, 0], xyz[:, 1], xyz[:, 2], label=title + '_water', color=wcolor, ls='None', marker=kwargs.get('wmarker', '.'), ms=kwargs.get('wsize', 6)) hetero = atoms.select('not protein and not nucleic and not water') if hetero: for res in HierView(hetero).iterResidues(): xyz = res._getCoords() resname = res.getResname() resnum = str(res.getResnum()) chid = res.getChid() show.plot(xyz[:, 0], xyz[:, 1], xyz[:, 2], ls='None', color=kwargs.get(resname, cnames.pop()).lower(), label=title + '_' + chid + '_' + resname + resnum, marker=kwargs.get('hmarker', 'o'), ms=kwargs.get('hsize', 6)) xyz = atoms._getCoords() min_.append(xyz.min(0)) max_.append(xyz.max(0)) show.set_xlabel('x') show.set_ylabel('y') show.set_zlabel('z') min_ = np.array(min_).min(0) max_ = np.array(max_).max(0) center = (max_ + min_) / 2 half = (max_ - min_).max() / 2 show.set_xlim3d(center[0]-half, center[0]+half) show.set_ylim3d(center[1]-half, center[1]+half) show.set_zlim3d(center[2]-half, center[2]+half) if kwargs.get('legend', False): show.legend(prop={'size': 10}) if SETTINGS['auto_show']: showFigure() return show