File: test_mmcif_writer.cc

package info (click to toggle)
openstructure 2.11.1-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 206,240 kB
  • sloc: cpp: 188,571; python: 36,686; ansic: 34,298; fortran: 3,275; sh: 312; xml: 146; makefile: 29
file content (439 lines) | stat: -rw-r--r-- 19,027 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
//------------------------------------------------------------------------------
// This file is part of the OpenStructure project <www.openstructure.org>
//
// Copyright (C) 2008-2024 by the OpenStructure authors
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License as published by the Free
// Software Foundation; either version 3.0 of the License, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
// details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this library; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//------------------------------------------------------------------------------

#define BOOST_TEST_DYN_LINK
#include <boost/test/unit_test.hpp>

#include <ost/conop/conop.hh>
#include <ost/conop/heuristic.hh>
#include <ost/io/mol/mmcif_writer.hh>
#include <ost/mol/mol.hh>
#include <ost/platform.hh>
#include <ost/log.hh>

using namespace ost;
using namespace ost::conop;
using namespace ost::io;

BOOST_AUTO_TEST_SUITE( io );

CompoundLibPtr load_lib()
{
  if (!getenv("OST_ROOT")) {
    LOG_ERROR("OST_ROOT environment variable not set. Can't load "
              "compound library without a proper OST_ROOT");
    return CompoundLibPtr();
  }
  SetPrefixPath(getenv("OST_ROOT"));
  String lib_path=GetSharedDataPath()+"/compounds.chemlib";
  CompoundLibPtr compound_lib=CompoundLib::Load(lib_path);
  return compound_lib;
}

BOOST_AUTO_TEST_CASE(mmcif_writer_force_hetatm)
{
  CompoundLibPtr lib = load_lib();
   if (!lib) { return; }
  BOOST_TEST_MESSAGE("  Running mmcif_force_hetatm tests...");
  /*
    Make sure that atoms set to HETATM are written as HETATM. There is some
    logic in place to deal with HETAM for mmcif_conform=false, check that this
    is working.
   */
  // Create small entity
  mol::EntityHandle ent=mol::CreateEntity();
  mol::XCSEditor edi=ent.EditXCS();
  mol::ChainHandle ch=edi.InsertChain("A");
  mol::ResidueHandle r1=edi.AppendResidue(ch, "GLY");
  edi.InsertAtom(r1, "N", geom::Vec3(1, 1, 1), "N", 1.0, 0.0, true);
  edi.InsertAtom(r1, "C", geom::Vec3(4, 1, 2), "C", 1.0, 0.0, true);
  mol::ResidueHandle r2=edi.AppendResidue(ch, "GLY");
  edi.InsertAtom(r2, "N", geom::Vec3(5, 2, 3), "N", 1.0, 0.0, true);
  edi.InsertAtom(r2, "C", geom::Vec3(4, 1, 1), "C", 1.0, 0.0, true);
  mol::ResidueHandle r3=edi.AppendResidue(ch, "GLY");
  edi.InsertAtom(r3, "N", geom::Vec3(5, 2, 2), "N", 1.0, 0.0, true);
  edi.InsertAtom(r3, "C", geom::Vec3(4, 1, 0), "C", 1.0, 0.0, true);
  edi.SetChainType(ch, mol::CHAINTYPE_UNKNOWN);
  // make sure we have a proper polypeptide
  conop::HeuristicProcessor heu_proc;
  heu_proc.Process(ent);
  BOOST_CHECK_EQUAL(mol::InSequence(r1, r2), true);
  BOOST_CHECK_EQUAL(mol::InSequence(r2, r3), true);

  // Create mmCIF stream
  MMCifWriter writer;
  writer.SetStructure(ent, lib, false);
  std::stringstream out;
  writer.Write("test", out);

  String s=out.str();
  // make sure the entity is a polymer
  BOOST_CHECK_NE(s.find("_entity.id\n_entity.type\n1 polymer"), String::npos);
  // check all atom records to be HETATMs
  for(auto i: ch.GetAtomList()){
    BOOST_CHECK_NE(s.find("HETATM "+
                          i.GetElement()+" "+
                          i.GetName()+" "+
                          i.GetResidue().GetName()),
                   String::npos);
  }

  // check that ATOM is written, if HETATM is not set
  // Create small entity
  ent=mol::CreateEntity();
  edi=ent.EditXCS();
  ch=edi.InsertChain("A");
  r1=edi.AppendResidue(ch, "GLY");
  edi.InsertAtom(r1, "N", geom::Vec3(1, 1, 1), "N");
  edi.InsertAtom(r1, "C", geom::Vec3(4, 1, 2), "C");
  r2=edi.AppendResidue(ch, "GLY");
  edi.InsertAtom(r2, "N", geom::Vec3(5, 2, 3), "N");
  edi.InsertAtom(r2, "C", geom::Vec3(4, 1, 1), "C");
  r3=edi.AppendResidue(ch, "GLY");
  edi.InsertAtom(r3, "N", geom::Vec3(5, 2, 2), "N");
  edi.InsertAtom(r3, "C", geom::Vec3(4, 1, 0), "C");
  edi.SetChainType(ch, mol::CHAINTYPE_UNKNOWN);
  // make sure we have a proper polypeptide
  heu_proc.Process(ent);
  BOOST_CHECK_EQUAL(mol::InSequence(r1, r2), true);
  BOOST_CHECK_EQUAL(mol::InSequence(r2, r3), true);

  // Create mmCIF stream
  writer=MMCifWriter();
  writer.SetStructure(ent, lib, false);
  out=std::stringstream();
  writer.Write("test", out);

  s=out.str();
  // make sure the entity is a polymer
  BOOST_CHECK_NE(s.find("_entity.id\n_entity.type\n1 polymer"), String::npos);
  // check all atom records to be ATOMs
  for(auto i: ch.GetAtomList()){
    BOOST_CHECK_NE(s.find("ATOM "+
                          i.GetElement()+" "+
                          i.GetName()+" "+
                          i.GetResidue().GetName()),
                   String::npos);
  }

  BOOST_TEST_MESSAGE("  done.");
}

BOOST_AUTO_TEST_CASE(mmcif_writer_entity1)
{
  CompoundLibPtr lib = load_lib();
   if (!lib) { return; }
  BOOST_TEST_MESSAGE("  Running mmcif_writer_entity1 tests...");
  /*
    Make sure molecular entities in mmCIF files written by OST start counting
    at ID 1. This is not enforced by the mmCIF format definition, but common
    practice.
   */

  // Create tiny entity
  mol::EntityHandle ent=mol::CreateEntity();
  mol::XCSEditor edi=ent.EditXCS();
  mol::ChainHandle ch=edi.InsertChain("A");
  mol::ResidueHandle r=edi.AppendResidue(ch, "GLY");
  edi.InsertAtom(r, "CA", geom::Vec3(32.0, -128.0, -2.5), "C");
  edi.SetChainType(ch, mol::CHAINTYPE_UNKNOWN);

  // Create mmCIF stream
  MMCifWriter writer;
  writer.SetStructure(ent, lib, false);
  std::stringstream out;
  writer.Write("test", out);

  // Check if entity starts with 1, either by reading mmCIF or "grep"
  String s=out.str();
  BOOST_CHECK_NE(s.find("_entity.id\n_entity.type\n1 non-polymer"),
                 String::npos);

  BOOST_TEST_MESSAGE("  done.");
}

BOOST_AUTO_TEST_CASE(mmcif_writer_poly_vs_non_poly)
{
  CompoundLibPtr lib = load_lib();
   if (!lib) { return; }
  BOOST_TEST_MESSAGE("  Running mmcif_writer_poly_vs_non_poly tests...");
  /*
    Go for small polymers that are not polymer... the story of 2 amino acids (to
    be handled like RCSB as 2 separated chains) plus how the same thing works
    for nucleic acids.
   */

  // Polypeptide: 2aa in a chain are 2 separated entities for RCSB (check 1E8K)
  mol::EntityHandle ent=mol::CreateEntity();
  mol::XCSEditor edi=ent.EditXCS();
  mol::ChainHandle ch=edi.InsertChain("A");
  edi.SetChainType(ch, mol::CHAINTYPE_POLY_PEPTIDE_L);
  // ALA
  mol::ResidueHandle r1=edi.AppendResidue(ch, "ALA");
  edi.InsertAtom(r1, "N",  geom::Vec3(44.987, 17.389, 12.362), "N");
  edi.InsertAtom(r1, "CA", geom::Vec3(45.936, 16.434, 12.890), "C");
  edi.InsertAtom(r1, "C",  geom::Vec3(47.196, 17.227, 13.152), "C");
  edi.InsertAtom(r1, "O",  geom::Vec3(47.506, 18.153, 12.401), "O");
  edi.InsertAtom(r1, "CB", geom::Vec3(46.244, 15.293, 11.961), "C");
  // PRO
  mol::ResidueHandle r2=edi.AppendResidue(ch, "PRO");
  edi.InsertAtom(r2, "N",   geom::Vec3(47.953, 16.910, 14.229), "N");
  edi.InsertAtom(r2, "CA",  geom::Vec3(47.673, 15.829, 15.187), "C");
  edi.InsertAtom(r2, "C",   geom::Vec3(46.564, 16.052, 16.233), "C");
  edi.InsertAtom(r2, "O",   geom::Vec3(46.059, 17.169, 16.417), "O");
  edi.InsertAtom(r2, "CB",  geom::Vec3(49.054, 15.755, 15.880), "C");
  edi.InsertAtom(r2, "CG",  geom::Vec3(49.357, 17.213, 16.030), "C");
  edi.InsertAtom(r2, "CD",  geom::Vec3(49.098, 17.714, 14.637), "C");
  edi.InsertAtom(r2, "OXT", geom::Vec3(46.144, 15.129, 16.950), "O");

  // Make sure that the two residues r1, r2 are actually connected
  conop::HeuristicProcessor heu_proc;
  heu_proc.Process(ent);
  BOOST_CHECK_EQUAL(mol::InSequence(r1, r2), true);

  // Create mmCIF stream
  MMCifWriter writer;
  writer.SetStructure(ent, lib, false);
  std::stringstream out;
  writer.Write("test", out);

  String s=out.str();
  // Check that the mmCIF output contains 2 non-polymer entities
  BOOST_CHECK_NE(
        s.find("loop_\n_entity.id\n_entity.type\n1 non-polymer\n2 non-polymer"),
        String::npos);
  BOOST_CHECK_NE(
             s.find("loop_\n_struct_asym.id\n_struct_asym.entity_id\nA 1\nB 2"),
             String::npos);
  // Check that atoms are HETATMs since non-poly
  BOOST_CHECK_NE(s.find("HETATM N N ALA"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C CA ALA"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C C ALA"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM O O ALA"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C CB ALA"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM N N PRO"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C CA PRO"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C C PRO"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM O O PRO "), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C CB PRO"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C CG PRO"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM C CD PRO"), String::npos);
  BOOST_CHECK_NE(s.find("HETATM O OXT PRO"), String::npos);

  // Nucleic acid: 2 bases in a chain are 2 entities for RCSB (check 4K9A)
  ent=mol::CreateEntity();
  edi=ent.EditXCS();
  ch=edi.InsertChain("A");
  edi.SetChainType(ch, mol::CHAINTYPE_POLY_RN);
  // G
  r1=edi.AppendResidue(ch, "G");
  r1.SetChemClass(mol::ChemClass('R'));
  edi.InsertAtom(r1, "OP3", geom::Vec3(-19.992, -12.612, -22.535), "O");
  edi.InsertAtom(r1, "P",   geom::Vec3(-20.743, -13.990, -22.451), "P");
  edi.InsertAtom(r1, "OP1", geom::Vec3(-20.093, -14.853, -23.494), "O");
  edi.InsertAtom(r1, "OP2", geom::Vec3(-20.592, -14.510, -21.074), "O");
  edi.InsertAtom(r1, "O5'", geom::Vec3(-22.258, -13.779, -22.864), "O");
  edi.InsertAtom(r1, "C5'", geom::Vec3(-22.956, -12.621, -22.414), "C");
  edi.InsertAtom(r1, "C4'", geom::Vec3(-24.433, -12.831, -22.071), "C");
  edi.InsertAtom(r1, "O4'", geom::Vec3(-24.958, -11.618, -21.688), "O");
  edi.InsertAtom(r1, "C3'", geom::Vec3(-25.196, -13.187, -23.283), "C");
  edi.InsertAtom(r1, "O3'", geom::Vec3(-26.335, -13.801, -22.833), "O");
  edi.InsertAtom(r1, "C2'", geom::Vec3(-25.568, -11.908, -23.910), "C");
  edi.InsertAtom(r1, "O2'", geom::Vec3(-26.792, -12.071, -24.602), "O");
  edi.InsertAtom(r1, "C1'", geom::Vec3(-25.819, -11.112, -22.709), "C");
  edi.InsertAtom(r1, "N9",  geom::Vec3(-25.646, -9.689,  -22.974), "N");
  edi.InsertAtom(r1, "C8",  geom::Vec3(-26.518, -8.728,  -22.814), "C");
  edi.InsertAtom(r1, "N7",  geom::Vec3(-25.994, -7.595,  -23.153), "N");
  edi.InsertAtom(r1, "C5",  geom::Vec3(-24.781, -7.838,  -23.527), "C");
  edi.InsertAtom(r1, "C6",  geom::Vec3(-23.815, -7.062,  -23.942), "C");
  edi.InsertAtom(r1, "O6",  geom::Vec3(-23.953, -5.880,  -24.055), "O");
  edi.InsertAtom(r1, "N1",  geom::Vec3(-22.652, -7.575,  -24.269), "N");
  edi.InsertAtom(r1, "C2",  geom::Vec3(-22.453, -8.886,  -24.153), "C");
  edi.InsertAtom(r1, "N2",  geom::Vec3(-21.312, -9.419,  -24.474), "N");
  edi.InsertAtom(r1, "N3",  geom::Vec3(-23.422, -9.638,  -23.738), "N");
  edi.InsertAtom(r1, "C4",  geom::Vec3(-24.577, -9.122,  -23.422), "C");
  // A
  r2=edi.AppendResidue(ch, "A");
  r2.SetChemClass(mol::ChemClass('R'));
  edi.InsertAtom(r2, "P",   geom::Vec3(-27.082, -11.572, -26.017), "P");
  edi.InsertAtom(r2, "OP1", geom::Vec3(-28.487, -11.993, -26.469), "O");
  edi.InsertAtom(r2, "OP2", geom::Vec3(-27.228, -10.079, -25.961), "O");
  edi.InsertAtom(r2, "O5'", geom::Vec3(-26.066, -11.826, -27.005), "O");
  edi.InsertAtom(r2, "C5'", geom::Vec3(-25.894, -13.010, -27.689), "C");
  edi.InsertAtom(r2, "C4'", geom::Vec3(-24.500, -13.055, -28.234), "C");
  edi.InsertAtom(r2, "O4'", geom::Vec3(-24.168, -11.802, -28.703), "O");
  edi.InsertAtom(r2, "C3'", geom::Vec3(-23.540, -13.333, -27.140), "C");
  edi.InsertAtom(r2, "O3'", geom::Vec3(-22.424, -13.995, -27.663), "O");
  edi.InsertAtom(r2, "C2'", geom::Vec3(-23.101, -11.988, -26.770), "C");
  edi.InsertAtom(r2, "O2'", geom::Vec3(-21.831, -12.081, -26.257), "O");
  edi.InsertAtom(r2, "C1'", geom::Vec3(-23.037, -11.318, -28.071), "C");
  edi.InsertAtom(r2, "N9",  geom::Vec3(-23.277, -9.902,  -27.855), "N");
  edi.InsertAtom(r2, "C8",  geom::Vec3(-24.331, -9.311,  -27.370), "C");
  edi.InsertAtom(r2, "N7",  geom::Vec3(-24.073, -8.040,  -27.362), "N");
  edi.InsertAtom(r2, "C5",  geom::Vec3(-22.856, -7.821,  -27.812), "C");
  edi.InsertAtom(r2, "C6",  geom::Vec3(-22.091, -6.735,  -27.998), "C");
  edi.InsertAtom(r2, "N6",  geom::Vec3(-22.544, -5.535,  -27.711), "N");
  edi.InsertAtom(r2, "N1",  geom::Vec3(-20.885, -6.823,  -28.480), "N");
  edi.InsertAtom(r2, "C2",  geom::Vec3(-20.381, -8.034,  -28.799), "C");
  edi.InsertAtom(r2, "N3",  geom::Vec3(-21.167, -9.113,  -28.595), "N");
  edi.InsertAtom(r2, "C4",  geom::Vec3(-22.379, -8.993,  -28.116), "C");

  // Make sure that the two residues r1, r2 are actually connected
  /* In the RCSB entry 4K9A, G O2' and A P are linked, but we force a regular
     nucleotide link for the test
  */
  edi.Connect(r1.FindAtom("O3'"), r2.FindAtom("P"));
  BOOST_CHECK_EQUAL(mol::InSequence(r1, r2), true);

  // Create mmCIF stream
  writer=MMCifWriter();
  writer.SetStructure(ent, lib, false);
  out=std::stringstream();
  writer.Write("test", out);

  s=out.str();
  // Check that the mmCIF output contains 2 non-polymer entities
  BOOST_CHECK_NE(
        s.find("loop_\n_entity.id\n_entity.type\n1 non-polymer\n2 non-polymer"),
        String::npos);
  BOOST_CHECK_NE(
             s.find("loop_\n_struct_asym.id\n_struct_asym.entity_id\nA 1\nB 2"),
             String::npos);
  // Check that atoms are HETATMs since non-poly
  for(auto i: ch.GetAtomList()){
    BOOST_CHECK_NE(s.find("HETATM "+
                          i.GetElement()+" "+
                          i.GetName()+" "+
                          i.GetResidue().GetName()),
                   String::npos);
  }

  BOOST_TEST_MESSAGE("  done.");
}

BOOST_AUTO_TEST_CASE(mmcif_writer_small_sugars)
{
  CompoundLibPtr lib = load_lib();
   if (!lib) { return; }
  BOOST_TEST_MESSAGE("  Running mmcif_writer_small_sugars tests...");
  /*
    While RCSB marks dipeptides and dinucleotides as non-ploymers, sugars are
    marked branched as soon as there are 2 connected.
   */
  // Branched: 2 sugars connected (check RCSB 3AXH)
  mol::EntityHandle ent=mol::CreateEntity();
  mol::XCSEditor edi=ent.EditXCS();
  mol::ChainHandle ch=edi.InsertChain("A");
  edi.SetChainType(ch, mol::CHAINTYPE_OLIGOSACCHARIDE);
  // GLC
  mol::ResidueHandle r1=edi.AppendResidue(ch, "GLC");
  r1.SetChemClass(mol::ChemClass('Y'));
  edi.InsertAtom(r1, "C1", geom::Vec3(-17.103, -7.005, -18.605), "C");
  edi.InsertAtom(r1, "C2", geom::Vec3(-18.238, -7.769, -17.910), "C");
  edi.InsertAtom(r1, "C3", geom::Vec3(-18.607, -9.018, -18.701), "C");
  edi.InsertAtom(r1, "C4", geom::Vec3(-18.909, -8.623, -20.136), "C");
  edi.InsertAtom(r1, "C5", geom::Vec3(-17.692, -7.925, -20.738), "C");
  edi.InsertAtom(r1, "C6", geom::Vec3(-17.985, -7.413, -22.123), "C");
  edi.InsertAtom(r1, "O1", geom::Vec3(-15.956, -7.805, -18.503), "O");
  edi.InsertAtom(r1, "O2", geom::Vec3(-17.855, -8.167, -16.612), "O");
  edi.InsertAtom(r1, "O3", geom::Vec3(-19.758, -9.617, -18.139), "O");
  edi.InsertAtom(r1, "O4", geom::Vec3(-19.249, -9.772, -20.895), "O");
  edi.InsertAtom(r1, "O5", geom::Vec3(-17.381, -6.775, -19.989), "O");
  edi.InsertAtom(r1, "O6", geom::Vec3(-19.210, -6.695, -22.028), "O");
  // GLC
  mol::ResidueHandle r2=edi.AppendResidue(ch, "GLC");
  r2.SetChemClass(mol::ChemClass('Y'));
  edi.InsertAtom(r2, "C1", geom::Vec3(-20.076, -6.111, -23.424), "C");
  edi.InsertAtom(r2, "C2", geom::Vec3(-21.506, -5.777, -22.960), "C");
  edi.InsertAtom(r2, "C3", geom::Vec3(-22.102, -7.005, -22.273), "C");
  edi.InsertAtom(r2, "C4", geom::Vec3(-22.152, -8.101, -23.352), "C");
  edi.InsertAtom(r2, "C5", geom::Vec3(-20.802, -8.397, -24.036), "C");
  edi.InsertAtom(r2, "C6", geom::Vec3(-21.027, -9.040, -25.414), "C");
  edi.InsertAtom(r2, "O2", geom::Vec3(-21.398, -4.714, -22.066), "O");
  edi.InsertAtom(r2, "O3", geom::Vec3(-23.396, -6.675, -21.796), "O");
  edi.InsertAtom(r2, "O4", geom::Vec3(-22.738, -9.283, -22.830), "O");
  edi.InsertAtom(r2, "O5", geom::Vec3(-20.007, -7.236, -24.284), "O");
  edi.InsertAtom(r2, "O6", geom::Vec3(-21.528, -8.081, -26.325), "O");

  // Connect the two sugars
  edi.Connect(r1.FindAtom("O6"), r2.FindAtom("C1"));

  // Create mmCIF stream
  MMCifWriter writer;
  writer.SetStructure(ent, lib, false);
  std::stringstream out;
  writer.Write("test", out);

  String s=out.str();
  // Check that the mmCIF output contains a branched entity
  BOOST_CHECK_NE(s.find("loop_\n_entity.id\n_entity.type\n1 branched"),
                 String::npos);
  // Check that atoms are HETATMs since non-poly
  for(auto i: ch.GetAtomList()){
    BOOST_CHECK_NE(s.find("HETATM "+
                          i.GetElement()+" "+
                          i.GetName()+" "+
                          i.GetResidue().GetName()),
                   String::npos);
  }

  // Non-poly: single sugar (check RCSB 1BDG)
  ent=mol::CreateEntity();
  edi=ent.EditXCS();
  ch=edi.InsertChain("A");
  edi.SetChainType(ch, mol::CHAINTYPE_OLIGOSACCHARIDE);
  // GLC
  r1=edi.AppendResidue(ch, "GLC");
  r1.SetChemClass(mol::ChemClass('Y'));
  edi.InsertAtom(r1, "C1", geom::Vec3(-17.103, -7.005, -18.605), "C");
  edi.InsertAtom(r1, "C2", geom::Vec3(-18.238, -7.769, -17.910), "C");
  edi.InsertAtom(r1, "C3", geom::Vec3(-18.607, -9.018, -18.701), "C");
  edi.InsertAtom(r1, "C4", geom::Vec3(-18.909, -8.623, -20.136), "C");
  edi.InsertAtom(r1, "C5", geom::Vec3(-17.692, -7.925, -20.738), "C");
  edi.InsertAtom(r1, "C6", geom::Vec3(-17.985, -7.413, -22.123), "C");
  edi.InsertAtom(r1, "O1", geom::Vec3(-15.956, -7.805, -18.503), "O");
  edi.InsertAtom(r1, "O2", geom::Vec3(-17.855, -8.167, -16.612), "O");
  edi.InsertAtom(r1, "O3", geom::Vec3(-19.758, -9.617, -18.139), "O");
  edi.InsertAtom(r1, "O4", geom::Vec3(-19.249, -9.772, -20.895), "O");
  edi.InsertAtom(r1, "O5", geom::Vec3(-17.381, -6.775, -19.989), "O");
  edi.InsertAtom(r1, "O6", geom::Vec3(-19.210, -6.695, -22.028), "O");

  // Create mmCIF stream
  writer=MMCifWriter();
  writer.SetStructure(ent, lib, false);
  out = std::stringstream();
  writer.Write("test", out);

  s=out.str();
  // Check that the mmCIF output contains 2 non-polymer entities
  BOOST_CHECK_NE(s.find("loop_\n_entity.id\n_entity.type\n1 non-polymer"),
                 String::npos);
  // Check that atoms are HETATMs since non-poly
  for(auto i: ch.GetAtomList()){
    BOOST_CHECK_NE(s.find("HETATM "+
                          i.GetElement()+" "+
                          i.GetName()+" "+
                          i.GetResidue().GetName()),
                   String::npos);
  }

  BOOST_TEST_MESSAGE("  done.");
}

BOOST_AUTO_TEST_SUITE_END();