add micro het todos and example pdb id

docs/interesting-pdb-entries.md

@@ -2,7 +2,9 @@
 * B-DNA (1bna)
 * Missing carbonyl oxygen (1gfl)
 * Mono-saccharides with alt locs (1B5F)
-* Microheterogeneity (1EJG, 3NIR)
+* Microheterogeneity
+    * Protein (1EJG, 3NIR)
+    * DNA (3VOK)
 * PNA: peptide nucleic acid (5eme, 1xj9)
 * Peptide derived residues
     * GFP chromophores (5Z6Y)

src/mol-repr/structure/visual/nucleotide-block-mesh.ts

@@ -22,6 +22,8 @@ import { VisualUpdateState } from '../../util';
 import { BaseGeometry } from '../../../mol-geo/geometry/base';
 import { Sphere3D } from '../../../mol-math/geometry';
 
+// TODO support blocks for multiple locations (including from microheterogeneity)
+
 const p1 = Vec3.zero();
 const p2 = Vec3.zero();
 const p3 = Vec3.zero();

src/mol-repr/structure/visual/nucleotide-ring-mesh.ts

@@ -23,6 +23,8 @@ import { VisualUpdateState } from '../../util';
 import { BaseGeometry } from '../../../mol-geo/geometry/base';
 import { Sphere3D } from '../../../mol-math/geometry';
 
+// TODO support rings for multiple locations (including from microheterogeneity)
+
 const pTrace = Vec3.zero();
 const pN1 = Vec3.zero();
 const pC2 = Vec3.zero();