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 +
{{Infobox script-repo
 +
|type      = script
 +
|filename  = aaindex.py
 +
|author    = [[User:Speleo3|Thomas Holder]]
 +
|license  = BSD
 +
}}
 +
 +
== Introduction ==
 +
[[File:AAindexExample.png|200px|thumb|right|Hydrophobicity coloring with KYTJ820101]]
 +
 
AAindex is a database of numerical indices representing various physicochemical and biochemical properties of amino acids and pairs of amino acids. See http://www.genome.jp/aaindex/
 
AAindex is a database of numerical indices representing various physicochemical and biochemical properties of amino acids and pairs of amino acids. See http://www.genome.jp/aaindex/
  
−
This script is a python parser for the AAindex flat files which you have to download:
+
This script is a python parser for the AAindex flat files which will be downloaded from ftp://ftp.genome.jp/pub/db/community/aaindex/
−
 
 
−
* ftp://ftp.genome.jp/pub/db/community/aaindex/aaindex1
 
−
* ftp://ftp.genome.jp/pub/db/community/aaindex/aaindex2
 
−
* ftp://ftp.genome.jp/pub/db/community/aaindex/aaindex3
 
  
 
The script provides two PyMOL commands (but can also be used without PyMOL).
 
The script provides two PyMOL commands (but can also be used without PyMOL).
Line 12: Line 18:
 
* pmf: Potential of Mean Force (aaindex3)
 
* pmf: Potential of Mean Force (aaindex3)
  
−
= Python Example =
+
== Python Example ==
  
 
Consider the script is called aaindex.py, it is placed somewhere in your PYTHONPATH and the aaindex flatfiles are found in the current directory.
 
Consider the script is called aaindex.py, it is placed somewhere in your PYTHONPATH and the aaindex flatfiles are found in the current directory.
Line 22: Line 28:
 
aaindex.grep('volume')
 
aaindex.grep('volume')
 
x = aaindex.get('KRIW790103')
 
x = aaindex.get('KRIW790103')
−
print x
+
print(x)
−
print x.get('A')
+
print(x.get('A'))
  
 +
aaindex.init(index='2')
 
aaindex.grep('blosum')
 
aaindex.grep('blosum')
 
x = aaindex.get('HENS920102')
 
x = aaindex.get('HENS920102')
−
print x.get('A', 'K')
+
print(x.get('A', 'K'))
 
</source>
 
</source>
  
−
= PyMOL Example =
+
== PyMOL Example ==
  
 
<source lang="python">
 
<source lang="python">
 
import aaindex
 
import aaindex
−
aaindex.init(path='.')
 
−
 
 
aaindex2b KYTJ820101
 
aaindex2b KYTJ820101
 
spectrum b, yellow_white_blue
 
spectrum b, yellow_white_blue
Line 41: Line 46:
 
</source>
 
</source>
  
−
= The Script =
+
== See Also ==
−
<source lang="python">
 
−
'''
 
−
(c) 2010 Thomas Holder
 
−
 
 
−
Python parser for AAindex: Amino Acid Index Database
 
−
http://www.genome.jp/aaindex/
 
−
 
 
−
PyMOL commands:
 
−
 
 
−
    aaindex2b
 
−
    pmf
 
−
'''
 
−
 
 
−
_aaindex = dict()
 
−
_pymol_auto_arg_update = lambda: None
 
−
 
 
−
def search(pattern, searchtitle=True, casesensitive=False):
 
−
    '''
 
−
    Search for pattern in description and title (optional) of all records and
 
−
    return matched records as list. By default search case insensitive.
 
−
    '''
 
−
    whatcase = lambda i: i
 
−
    if not casesensitive:
 
−
        pattern = pattern.lower()
 
−
        whatcase = lambda i: i.lower()
 
−
    matches = []
 
−
    for record in _aaindex.itervalues():
 
−
        if pattern in whatcase(record.desc) or searchtitle and pattern in whatcase(record.title):
 
−
            matches.append(record)
 
−
    return matches
 
−
 
 
−
def grep(pattern):
 
−
    '''
 
−
    Search for pattern in title and description of all records (case
 
−
    insensitive) and print results on standard output.
 
−
    '''
 
−
    for record in search(pattern):
 
−
        print record
 
−
 
 
−
class Record:
 
−
    '''
 
−
    Amino acid index (AAindex) Record
 
−
    '''
 
−
    aakeys = 'ARNDCQEGHILKMFPSTWYV'
 
−
    def __init__(self):
 
−
        self.key = None
 
−
        self.desc = ''
 
−
        self.ref = ''
 
−
        self.authors = ''
 
−
        self.title = ''
 
−
        self.journal = ''
 
−
        self.correlated = dict()
 
−
        self.index = dict()
 
−
        self.comment = ''
 
−
    def extend(self, row):
 
−
        i = len(self.index)
 
−
        for x in row:
 
−
            self.index[self.aakeys[i]] = x
 
−
            i += 1
 
−
    def get(self, aai, aaj=None, d=None):
 
−
        assert aaj is None
 
−
        return self.index.get(aai, d)
 
−
    def median(self):
 
−
        x = sorted(filter(None, self.index.values()))
 
−
        half = len(x)/2
 
−
        if len(x) % 2 == 1:
 
−
            return x[half]
 
−
        return (x[half-1] + x[half])/2.0
 
−
    def __str__(self):
 
−
        desc = self.desc.replace('\n', ' ').strip()
 
−
        return '%s(%s: %s)' % (self.__class__.__name__, self.key, desc)
 
−
 
 
−
class MatrixRecord(Record):
 
−
    '''
 
−
    Matrix record for mutation matrices or pair-wise contact potentials
 
−
    '''
 
−
    def __init__(self):
 
−
        Record.__init__(self)
 
−
        self.index = []
 
−
        self.rows = dict()
 
−
        self.cols = dict()
 
−
    def extend(self, row):
 
−
        self.index.append(row)
 
−
    def _get(self, aai, aaj):
 
−
        i = self.rows[aai]
 
−
        j = self.cols[aaj]
 
−
        return self.index[i][j]
 
−
    def get(self, aai, aaj, d=None):
 
−
        try:
 
−
            return self._get(aai, aaj)
 
−
        except:
 
−
            pass
 
−
        try:
 
−
            return self._get(aaj, aai)
 
−
        except:
 
−
            return d
 
−
    def median(self):
 
−
        x = []
 
−
        for y in self.index:
 
−
            x.extend(filter(None, y))
 
−
        x.sort()
 
−
        if len(x) % 2 == 1:
 
−
            return x[len(x)/2]
 
−
        return sum(x[len(x)/2-1:len(x)/2+1])/2.0
 
−
 
 
−
def get(key):
 
−
    '''
 
−
    Get record for key
 
−
    '''
 
−
    if len(_aaindex) == 0:
 
−
        init()
 
−
    return _aaindex.get(key)
 
−
 
 
−
def _float_or_None(x):
 
−
    if x == 'NA' or x == '-':
 
−
        return None
 
−
    return float(x)
 
−
 
 
−
def init(path=None, index='123'):
 
−
    '''
 
−
    Read in the aaindex files. You need to run this (once) before you can
 
−
    access any records. If the files are not within the current directory,
 
−
    you need to specify the correct directory path. By default all three
 
−
    aaindex files are read in.
 
−
    '''
 
−
    if path is None:
 
−
        import sys
 
−
        from os.path import sep
 
−
        path = __file__.rsplit(sep, 1)[0]
 
−
        print >> sys.stderr, 'path =', path
 
−
    index = str(index)
 
−
    if '1' in index:
 
−
        _parse(path + '/aaindex1', Record)
 
−
    if '2' in index:
 
−
        _parse(path + '/aaindex2', MatrixRecord)
 
−
    if '3' in index:
 
−
        _parse(path + '/aaindex3', MatrixRecord)
 
−
    _pymol_auto_arg_update()
 
−
 
 
−
def init_from_file(filename, type=Record):
 
−
    _parse(filename, type)
 
−
 
 
−
def _parse(filename, rec, quiet=True):
 
−
    '''
 
−
    Parse aaindex input file. `rec` must be `Record` for aaindex1 and
 
−
    `MarixRecord` for aaindex2 and aaindex3.
 
−
    '''
 
−
    try:
 
−
        f = file(filename, 'rU')
 
−
    except:
 
−
        print ('Cannot open "%s", please download it from ' + \
 
−
                'ftp://ftp.genome.jp/pub/db/community/aaindex/') % filename
 
−
        return
 
−
 
 
−
    current = rec()
 
−
    lastkey = None
 
−
 
 
−
    for line in f:
 
−
        key = line[0:2]
 
−
        if key[0] == ' ':
 
−
            key = lastkey
 
−
 
 
−
        if key == '//':
 
−
            _aaindex[current.key] = current
 
−
            current = rec()
 
−
        elif key == 'H ':
 
−
            current.key = line[2:].strip()
 
−
        elif key == 'R ':
 
−
            current.ref += line[2:]
 
−
        elif key == 'D ':
 
−
            current.desc += line[2:]
 
−
        elif key == 'A ':
 
−
            current.authors += line[2:]
 
−
        elif key == 'T ':
 
−
            current.title += line[2:]
 
−
        elif key == 'J ':
 
−
            current.journal += line[2:]
 
−
        elif key == '* ':
 
−
            current.comment += line[2:]
 
−
        elif key == 'C ':
 
−
            a = line[2:].split()
 
−
            for i in range(0, len(a), 2):
 
−
                current.correlated[a[i]] = float(a[i+1])
 
−
        elif key == 'I ':
 
−
            a = line[1:].split()
 
−
            if a[0] != 'A/L':
 
−
                current.extend(map(_float_or_None, a))
 
−
            elif list(Record.aakeys) != [i[0] for i in a] + [i[-1] for i in a]:
 
−
                print 'Warning: wrong amino acid sequence for', current.key
 
−
            else:
 
−
                try:
 
−
                    assert list(Record.aakeys[:10]) == [i[0] for i in a]
 
−
                    assert list(Record.aakeys[10:]) == [i[2] for i in a]
 
−
                except:
 
−
                    print 'Warning: wrong amino acid sequence for', current.key
 
−
        elif key =='M ':
 
−
            a = line[2:].split()
 
−
            if a[0] == 'rows':
 
−
                if a[4] == 'rows':
 
−
                    a.pop(4)
 
−
                assert a[3] == 'cols' and len(a) == 6
 
−
                i = 0
 
−
                for aa in a[2]:
 
−
                    current.rows[aa] = i
 
−
                    i += 1
 
−
                i = 0
 
−
                for aa in a[5]:
 
−
                    current.cols[aa] = i
 
−
                    i += 1
 
−
            else:
 
−
                current.extend(map(_float_or_None, a))
 
−
        elif not quiet:
 
−
            print 'Warning: line starts with "%s"' % (key)
 
−
 
 
−
        lastkey = key
 
−
 
 
−
########## PYMOL ###########
 
−
 
 
−
# from Bio.SCOP.Raf import to_one_letter_code
 
−
# See also http://www.pymolwiki.org/index.php/Aa_codes
 
−
to_one_letter_code = {'PAQ': 'Y', 'AGM': 'R', 'ILE': 'I', 'PR3': 'C',
 
−
      'GLN': 'Q', 'DVA': 'V', 'CCS': 'C', 'ACL': 'R', 'GLX': 'Z', 'GLY': 'G',
 
−
      'GLZ': 'G', 'DTH': 'T', 'OAS': 'S', 'C6C': 'C', 'NEM': 'H', 'DLY': 'K',
 
−
      'MIS': 'S', 'SMC': 'C', 'GLU': 'E', 'NEP': 'H', 'BCS': 'C', 'ASQ': 'D',
 
−
      'ASP': 'D', 'SCY': 'C', 'SER': 'S', 'LYS': 'K', 'SAC': 'S', 'PRO': 'P',
 
−
      'ASX': 'B', 'DGN': 'Q', 'DGL': 'E', 'MHS': 'H', 'ASB': 'D', 'ASA': 'D',
 
−
      'NLE': 'L', 'DCY': 'C', 'ASK': 'D', 'GGL': 'E', 'STY': 'Y', 'SEL': 'S',
 
−
      'CGU': 'E', 'ASN': 'N', 'ASL': 'D', 'LTR': 'W', 'DAR': 'R', 'VAL': 'V',
 
−
      'CHG': 'A', 'TPO': 'T', 'CLE': 'L', 'GMA': 'E', 'HAC': 'A', 'AYA': 'A',
 
−
      'THR': 'T', 'TIH': 'A', 'SVA': 'S', 'MVA': 'V', 'SAR': 'G', 'LYZ': 'K',
 
−
      'BNN': 'A', '5HP': 'E', 'IIL': 'I', 'SHR': 'K', 'HAR': 'R', 'FME': 'M',
 
−
      'PYX': 'C', 'ALO': 'T', 'PHI': 'F', 'ALM': 'A', 'PHL': 'F', 'MEN': 'N',
 
−
      'TPQ': 'A', 'GSC': 'G', 'PHE': 'F', 'ALA': 'A', 'MAA': 'A', 'MET': 'M',
 
−
      'UNK': 'X', 'LEU': 'L', 'ALY': 'K', 'SET': 'S', 'GL3': 'G', 'TRG': 'K',
 
−
      'CXM': 'M', 'TYR': 'Y', 'SCS': 'C', 'DIL': 'I', 'TYQ': 'Y', '3AH': 'H',
 
−
      'DPR': 'P', 'PRR': 'A', 'CME': 'C', 'IYR': 'Y', 'CY1': 'C', 'TYY': 'Y',
 
−
      'HYP': 'P', 'DTY': 'Y', '2AS': 'D', 'DTR': 'W', 'FLA': 'A', 'DPN': 'F',
 
−
      'DIV': 'V', 'PCA': 'E', 'MSE': 'M', 'MSA': 'G', 'AIB': 'A', 'CYS': 'C',
 
−
      'NLP': 'L', 'CYQ': 'C', 'HIS': 'H', 'DLE': 'L', 'CEA': 'C', 'DAL': 'A',
 
−
      'LLP': 'K', 'DAH': 'F', 'HMR': 'R', 'TRO': 'W', 'HIC': 'H', 'CYG': 'C',
 
−
      'BMT': 'T', 'DAS': 'D', 'TYB': 'Y', 'BUC': 'C', 'PEC': 'C', 'BUG': 'L',
 
−
      'CYM': 'C', 'NLN': 'L', 'CY3': 'C', 'HIP': 'H', 'CSO': 'C', 'TPL': 'W',
 
−
      'LYM': 'K', 'DHI': 'H', 'MLE': 'L', 'CSD': 'A', 'HPQ': 'F', 'MPQ': 'G',
 
−
      'LLY': 'K', 'DHA': 'A', 'DSN': 'S', 'SOC': 'C', 'CSX': 'C', 'OMT': 'M',
 
−
      'DSP': 'D', 'PTR': 'Y', 'TRP': 'W', 'CSW': 'C', 'EFC': 'C', 'CSP': 'C',
 
−
      'CSS': 'C', 'SCH': 'C', 'OCS': 'C', 'NMC': 'G', 'SEP': 'S', 'BHD': 'D',
 
−
      'KCX': 'K', 'SHC': 'C', 'C5C': 'C', 'HTR': 'W', 'ARG': 'R', 'TYS': 'Y',
 
−
      'ARM': 'R', 'DNP': 'A'}
 
−
 
 
−
def aaindex2b(key='KYTJ820101', selection='(all)', quiet=0, var='b'):
 
−
    '''
 
−
DESCRIPTION
 
−
 
 
−
    "aaindex" looks up the Amino Acid Index from
 
−
      http://www.genome.jp/aaindex/
 
−
    for the given key and assignes b-factors to the given selection. Unknown
 
−
    residues get the average index value assigned.
 
−
 
 
−
USAGE
 
−
 
 
−
    aaindex2b [key [, selection]]
 
−
 
 
−
ARGUMENTS
 
−
 
 
−
    key = string: Key of AAindex entry
 
−
 
 
−
    selection = string: atoms to assign b-factors {default: (all)}
 
−
 
 
−
EXAMPLE
 
−
 
 
−
    # Hydropathy index by Kyte-Doolittle
 
−
    aaindex2b KYTJ820101
 
−
    spectrumany b, white yellow forest
 
−
    show surface
 
−
    '''
 
−
    from pymol import cmd, stored
 
−
    entry = get(key)
 
−
    median = entry.median()
 
−
 
 
−
    if int(quiet) != 0:
 
−
        print entry.desc.strip()
 
−
 
 
−
    def lookup(resn):
 
−
        one_letter = to_one_letter_code.get(resn, 'X')
 
−
        value = entry.get(one_letter)
 
−
        if value is None:
 
−
            return median
 
−
        return value
 
−
    stored.aaindex = lookup
 
−
 
 
−
    cmd.alter(selection, var + '=stored.aaindex(resn)')
 
−
 
 
−
def pmf(key, cutoff=7.0, selection1='(name CB)', selection2='', state=1, quiet=1):
 
−
    '''
 
−
DESCRIPTION
 
−
 
 
−
    Potential of Mean Force
 
−
 
 
−
ARGUMENTS
 
−
 
 
−
    key = string: aaindex key
 
−
 
 
−
    cutoff = float: distance cutoff {default: 7.0}
 
−
    cutoff = (float, float): distance shell
 
−
 
 
−
    selection1 = string: atom selection {default: (name CB)}
 
−
 
 
−
    selection2 = string: atom selection {default: selection1}
 
−
 
 
−
NOTES
 
−
 
 
−
    Does also support a list of keys and a list of cutoffs to deal with
 
−
    multiple distance shells.
 
−
 
 
−
EXAMPLES
 
−
 
 
−
    # load databases
 
−
    aaindex.init('/path/to/aaindex/directory')
 
−
 
 
−
    # distance dependent c-beta contact potentials
 
−
    pmf SIMK990101, 5,        /2x19//A//CB
 
−
    pmf SIMK990102, [5, 7.5],  /2x19//A//CB
 
−
    pmf [SIMK990101, SIMK990102, SIMK990103], [0, 5, 7.5, 10], /2x19//A//CB
 
−
 
 
−
    # interface potential
 
−
    sidechaincenters 2x19_scc, 2x19
 
−
    pmf KESO980102, 7.0, /2x19_scc//A, /2x19_scc//B
 
−
    distance /2x19_scc//A, /2x19_scc//B, cutoff=7.0
 
−
    '''
 
−
    from pymol import cmd, stored
 
−
    from chempy import cpv
 
−
    if cmd.is_string(key):
 
−
        if key.lstrip().startswith('['):
 
−
            key = cmd.safe_alpha_list_eval(key)
 
−
        else:
 
−
            key = [key]
 
−
    if cmd.is_string(cutoff):
 
−
        cutoff = eval(cutoff)
 
−
    if not cmd.is_sequence(cutoff):
 
−
        cutoff = [cutoff]
 
−
    if len(cutoff) == len(key):
 
−
        cutoff = [0.0] + list(cutoff)
 
−
    if len(cutoff) != len(key) + 1:
 
−
        print 'Error: Number of keys and number of cutoffs inconsistent'
 
−
        return
 
−
    state = int(state)
 
−
    quiet = int(quiet)
 
−
    if len(selection2) == 0:
 
−
        selection2 = selection1
 
−
    if not quiet and len(key) > 1:
 
−
        print 'Distance shells:'
 
−
        for i in range(len(key)):
 
−
            print '%s %.1f-%.1f' % (key[i], cutoff[i], cutoff[i+1])
 
−
 
 
−
    stored.idmap = dict()
 
−
    cmd.iterate_state(state, '(%s) or (%s)' % (selection1, selection2),
 
−
            'stored.idmap[model,index] = [(resn,name),(x,y,z)]')
 
−
    twoN = cmd.count_atoms(selection1) + cmd.count_atoms(selection2)
 
−
    pairs = cmd.find_pairs(selection1, selection2, cutoff=max(cutoff),
 
−
            state1=state, state2=state)
 
−
    if len(pairs) == 0:
 
−
        print 'Empty pair list'
 
−
        return 0.0
 
−
 
 
−
    matrix = map(get, key)
 
−
    for i in matrix:
 
−
        assert isinstance(i, MatrixRecord)
 
  
−
    i_list = range(len(key))
+
* Protscale from [http://www.rubor.de/pymol_extensions_de.html rTools] does a similar job in coloring by amino acid properties
−
    u_sum = 0
 
−
    count = 0
 
−
    for id1, id2 in pairs:
 
−
        a1 = stored.idmap[id1]
 
−
        a2 = stored.idmap[id2]
 
−
        r = cpv.distance(a1[1], a2[1])
 
−
        for i in i_list:
 
−
            if cutoff[i] <= r and r < cutoff[i+1]:
 
−
                try:
 
−
                    aa1 = to_one_letter_code[a1[0][0]]
 
−
                    aa2 = to_one_letter_code[a2[0][0]]
 
−
                    u_sum += matrix[i].get(aa1, aa2)
 
−
                    count += 1
 
−
                except:
 
−
                    print 'Failed for', a1[0], a2[0]
 
−
 
 
−
    value = float(u_sum) / twoN
 
−
    if not quiet:
 
−
        print 'PMF: %.4f (%d contacts, %d residues)' % (value, count, twoN)
 
−
    return value
 
−
 
 
−
try:
 
−
    from pymol import cmd
 
−
    cmd.extend('aaindex2b', aaindex2b)
 
−
    cmd.extend('pmf', pmf)
 
−
    def pymol_auto_arg_update():
 
−
        aaindexkey_sc = cmd.Shortcut(_aaindex.keys())
 
−
        cmd.auto_arg[0].update({
 
−
            'aaindex2b'  : [ aaindexkey_sc              , 'aaindexkey'      , ', ' ],
 
−
            'pmf'        : [ aaindexkey_sc              , 'aaindexkey'      , ', ' ],
 
−
        })
 
−
        cmd.auto_arg[1].update({
 
−
            'aaindex2b'  : [ cmd.selection_sc          , 'selection'      , ''  ],
 
−
        })
 
−
        cmd.auto_arg[2].update({
 
−
            'pmf'        : [ cmd.selection_sc          , 'selection'      , ''  ],
 
−
        })
 
−
        cmd.auto_arg[3].update({
 
−
            'pmf'        : [ cmd.selection_sc          , 'selection'      , ''  ],
 
−
        })
 
−
    _pymol_auto_arg_update = pymol_auto_arg_update
 
−
except:
 
−
    pass
 
−
 
 
−
# vi: ts=4:sw=4:smarttab:expandtab
 
−
</source>
 
  
−
[[Category:Plugins]]
+
[[Category:Script_Library]]
 
[[Category:Biochemical_Scripts]]
 
[[Category:Biochemical_Scripts]]
 
[[Category:Structural_Biology_Scripts]]
 
[[Category:Structural_Biology_Scripts]]
 +
[[Category:Pymol-script-repo]]

Latest revision as of 03:58, 4 March 2019

Type Python Script
Download aaindex.py
Author(s) Thomas Holder
License BSD
This code has been put under version control in the project Pymol-script-repo

Introduction

Hydrophobicity coloring with KYTJ820101

AAindex is a database of numerical indices representing various physicochemical and biochemical properties of amino acids and pairs of amino acids. See http://www.genome.jp/aaindex/

This script is a python parser for the AAindex flat files which will be downloaded from ftp://ftp.genome.jp/pub/db/community/aaindex/

The script provides two PyMOL commands (but can also be used without PyMOL).

  • aaindex2b: Loads numerical indices from aaindex1 as b-factors into your structure
  • pmf: Potential of Mean Force (aaindex3)

Python Example

Consider the script is called aaindex.py, it is placed somewhere in your PYTHONPATH and the aaindex flatfiles are found in the current directory.

import aaindex
aaindex.init(path='.')

aaindex.grep('volume')
x = aaindex.get('KRIW790103')
print(x)
print(x.get('A'))

aaindex.init(index='2')
aaindex.grep('blosum')
x = aaindex.get('HENS920102')
print(x.get('A', 'K'))

PyMOL Example

import aaindex
aaindex2b KYTJ820101
spectrum b, yellow_white_blue
show surface

See Also

  • Protscale from rTools does a similar job in coloring by amino acid properties