Source code for ccpn.core.Atom

Module documentation here
# Licence, Reference and Credits
__copyright__ = "Copyright (C) CCPN project ( 2014 - 2021"
__credits__ = ("Ed Brooksbank, Joanna Fox, Victoria A Higman, Luca Mureddu, Eliza Płoskoń",
               "Timothy J Ragan, Brian O Smith, Gary S Thompson & Geerten W Vuister")
__licence__ = ("CCPN licence. See")
__reference__ = ("Skinner, S.P., Fogh, R.H., Boucher, W., Ragan, T.J., Mureddu, L.G., & Vuister, G.W.",
                 "CcpNmr AnalysisAssign: a flexible platform for integrated NMR analysis",
                 "J.Biomol.Nmr (2016), 66, 111-124,")
# Last code modification
__modifiedBy__ = "$modifiedBy: Ed Brooksbank $"
__dateModified__ = "$dateModified: 2021-09-13 19:21:20 +0100 (Mon, September 13, 2021) $"
__version__ = "$Revision: 3.0.4 $"
# Created
__author__ = "$Author: CCPN $"
__date__ = "$Date: 2017-04-07 10:28:41 +0000 (Fri, April 07, 2017) $"
# Start of code

import typing

from ccpn.util import Common as commonUtil
from ccpn.core.lib import Pid
from ccpn.core.lib.Util import AtomIdTuple
from ccpn.core.Residue import Residue
from ccpn.core._implementation.AbstractWrapperObject import AbstractWrapperObject
from ccpnmodel.ccpncore.api.ccp.molecule.MolSystem import Atom as ApiAtom
from ccpn.core.lib.ContextManagers import newObject
from ccpn.util.Logging import getLogger

[docs]class Atom(AbstractWrapperObject): """A molecular Atom, contained in a Residue.""" #: Class name and Short class name, for PID. shortClassName = 'MA' # Attribute it necessary as subclasses must use superclass className className = 'Atom' _parentClass = Residue #: Name of plural link to instances of class _pluralLinkName = 'atoms' #: List of child classes. _childClasses = [] # Qualified name of matching API class _apiClassQualifiedName = ApiAtom._metaclass.qualifiedName() # CCPN properties @property def _apiAtom(self) -> ApiAtom: """ CCPN atom matching Atom""" return self._wrappedData @property def _parent(self) -> Residue: """Residue containing Atom.""" return self._project._data2Obj[self._wrappedData.residue] residue = _parent @property def _key(self) -> str: """Atom name string (e.g. 'HA') regularised as used for ID""" return @property def _idTuple(self) -> AtomIdTuple: """ID as chainCode, sequenceCode, residueType, atomName namedtuple NB Unlike the _id and key, these do NOT have reserved characters mapped to '^' NB _idTuple replaces empty strings with None""" parent = self._parent ll = [parent._parent.shortName, parent.sequenceCode, parent.residueType,] return AtomIdTuple(*(x or None for x in ll)) @property def name(self) -> str: """Atom name string (e.g. 'HA')""" return @property def boundAtoms(self) -> typing.Tuple['Atom']: """Atoms that are covalently bound to this Atom""" getDataObj = self._project._data2Obj.get apiAtom = self._wrappedData boundApiAtoms = list(apiAtom.boundAtoms) for apiBond in apiAtom.genericBonds: ll = list(apiBond.atoms) apiAtom2 = ll[0] if apiAtom is ll[1] else ll[1] boundApiAtoms.append(apiAtom2) boundAtoms = (getDataObj(x) for x in boundApiAtoms) return tuple(sorted(x for x in boundAtoms if x is not None)) @property def componentAtoms(self) -> typing.Tuple['Atom']: """Atoms that are combined to make up this atom - reverse of 'compoundAtoms' For simple atoms this is empty. For wildcard atoms (e.g. HB%, QB) this gives the individual atoms that combine into atom. For non-stereo atoms (e.g. HBx, HBy, HGx%) it gives the two alternative stereospecific atoms Compound atoms may be nested - e.g. Valine HG1% has the components HG11, HG12, HG13 and is itself a component of HGx%, HGy%, HG%, and QG""" getDataObj = self._project._data2Obj.get apiAtom = self._wrappedData return tuple(getDataObj(x) for x in self._wrappedData.components) @property def compoundAtoms(self) -> typing.Tuple['Atom']: """wildcard-, pseudo-, and nonstereo- atoms that incorporate this atom. - reverse of 'componentAtoms' Compound atoms may be nested - e.g. Valine HG1% has the components HG11, HG12, HG13 and is itself a component of HGx%, HGy%, HG%, and QG""" getDataObj = self._project._data2Obj.get apiAtom = self._wrappedData return tuple(getDataObj(x) for x in self._wrappedData.atomGroups) @property def exchangesWithWater(self) -> bool: """True if atom exchanges with water on a msx time scale, and so is mostly unobservable. Holds for e.g. OH atoms, NH£ groups and His side chain NH protons, but NOT for amide protons """ apiAtom = self._wrappedData components = apiAtom.components while components: for apiAtom in components: # Fastest way to get an arbitrary element from a frozen set break components = apiAtom.components # apiChemAtom = apiAtom.chemAtom if apiChemAtom: return apiChemAtom.waterExchangeable else: return False @property def isEquivalentAtomGroup(self) -> typing.Optional[bool]: """Is this atom a group of equivalent atoms? Values are: - True (group of equivalent atoms, e.g. H%, ALA HB%, LYS HZ%, VAL HG1% or any M pseudoatom) - False (all single atoms, all xy nonstereo atoms, LEU HB%, ILE HG1%, VAL HG%, or any Q non-aromatic pseudoatom) - None = sometimes equivalent (TYR and PHE HD%, HE%, CD%, CE%, QD, QE) """ apiChemAtomSet = self._wrappedData.chemAtomSet if apiChemAtomSet is None: return False else: # NB isEquivalent is None for symmetric aromatic rings. We return True for that return apiChemAtomSet.isEquivalent != False @property def elementSymbol(self): return self._wrappedData.elementSymbol
[docs] def addInterAtomBond(self, atom: 'Atom'): """ADVANCED Add generic bond between atoms - for creating disulfides or other crosslinks The bound-to atom will appear in self.boundAtoms. NB This function does not remove superfluous atoms (like CYS HG), or check for chemical plausibility. Programmer beware!""" project = self._project project._wrappedData.molSystem.newGenericBond(atoms=(self._wrappedData, atom._wrappedData))
#from ccpn.core.NmrAtom import NmrAtom: This will break the import sequence @property def nmrAtom(self) -> typing.Optional['NmrAtom']: """NmrAtom to which Atom is assigned NB Atom<->NmrAtom link depends solely on the NmrAtom name. So no notifiers on the link - notify on the NmrAtom rename instead. """ try: return self._project.getNmrAtom(self._id) except: return None # GWV 20181122: removed setters between Chain/NmrChain, Residue/NmrResidue, Atom/NmrAtom # @nmrAtom.setter # def nmrAtom(self, value:'NmrAtom'): # oldValue = self.nmrAtom # if oldValue is value: # return # elif value is None: # raise ValueError("Cannot set Atom.nmrAtom to None") # elif oldValue is not None: # raise ValueError("New assignment of Atom clashes with existing assignment") # else: # value.atom = self @property def isAssigned(self) -> bool: """ :return: True if Atom has as NmrAtom with an associated ChemicalShift object """ if self.nmrAtom is None: return False if not self.nmrAtom.chemicalShifts: return False # either None or len==0 return True #========================================================================================= # Implementation functions #========================================================================================= @classmethod def _getAllWrappedData(cls, parent: Residue) -> list: """get wrappedData (MolSystem.Atoms) for all Atom children of parent Residue""" return parent._wrappedData.sortedAtoms()
#========================================================================================= # CCPN functions #========================================================================================= #=========================================================================================== # new'Object' and other methods # Call appropriate routines in their respective locations #=========================================================================================== #========================================================================================= # Connections to parents: #========================================================================================= @newObject(Atom) def _newAtom(self: Residue, name: str, elementSymbol: str = None) -> 'Atom': """Create new Atom within Residue. If elementSymbol is None, it is derived from the name See the Atom class for details. :param name: :param elementSymbol: :return: a new Atom instance. """ from ccpn.util.isotopes import name2ElementSymbol lastAtom = self.getAtom(name) if lastAtom is not None: raise ValueError("Cannot create %s, atom name %s already in use" % (lastAtom.longPid, name)) if elementSymbol is None: elementSymbol = name2ElementSymbol(name) apiAtom = self._wrappedData.newAtom(name=name, elementSymbol=elementSymbol) result = self._project._data2Obj[apiAtom] if result is None: raise RuntimeError('Unable to generate new Atom item') apiAtom.expandNewAtom() return result #EJB 20181204: moved to Residue # Residue.newAtom = _newAtom # Connections to parents: