multiple possible sequence matches

[yaohe@…]

The following bug report has been submitted:
Platform:        Darwin-20.3.0-x86_64-i386-64bit
ChimeraX Version: 1.1.1 (2020-10-07 08:32:49 UTC)
Description
Sequence of DNA with repeatitive residues could not be shown correctly. 
The attached DNA has a sequence of (GTTGGG)5 and has G17-G30 in the corrordinate. Misseing residues from G1-G16 has been annotated in the pdb file. However, its sequence shown in ChimeraX is from G13 to G42 (see attached image). This also happens in Chimera with the same pdb file. 

OpenGL version: 4.1 INTEL-16.1.11
OpenGL renderer: Intel(R) Iris(TM) Graphics 6100
OpenGL vendor: Intel Inc.Hardware:

    Hardware Overview:

      Model Name: MacBook Pro
      Model Identifier: MacBookPro12,1
      Processor Name: Dual-Core Intel Core i5
      Processor Speed: 2.7 GHz
      Number of Processors: 1
      Total Number of Cores: 2
      L2 Cache (per Core): 256 KB
      L3 Cache: 3 MB
      Hyper-Threading Technology: Enabled
      Memory: 8 GB
      System Firmware Version: 426.0.0.0.0
      SMC Version (system): 2.28f7

Software:

    System Software Overview:

      System Version: macOS 11.2.1 (20D74)
      Kernel Version: Darwin 20.3.0
      Time since boot: 8:02

Graphics/Displays:

    Intel Iris Graphics 6100:

      Chipset Model: Intel Iris Graphics 6100
      Type: GPU
      Bus: Built-In
      VRAM (Dynamic, Max): 1536 MB
      Vendor: Intel
      Device ID: 0x162b
      Revision ID: 0x0009
      Metal Family: Supported, Metal GPUFamily macOS 1
      Displays:
        DELL U2417H:
          Resolution: 1080 x 1920
          UI Looks like: 1080 x 1920 @ 60.00Hz
          Framebuffer Depth: 24-Bit Color (ARGB8888)
          Display Serial Number: XVNNT08LAF1B
          Mirror: Off
          Online: Yes
          Rotation: 90
          Adapter Type: Thunderbolt/DisplayPort
          Automatically Adjust Brightness: Yes
        DELL U2717D:
          Resolution: 2560 x 1440 (QHD/WQHD - Wide Quad High Definition)
          UI Looks like: 2560 x 1440 @ 60.00Hz
          Framebuffer Depth: 24-Bit Color (ARGB8888)
          Display Serial Number: 67YGV97JB16U
          Main Display: Yes
          Mirror: Off
          Online: Yes
          Rotation: Supported
          Automatically Adjust Brightness: Yes

PyQt version: 5.12.3
Compiled Qt version: 5.12.4
Runtime Qt version: 5.12.9
Installed Packages:
    alabaster: 0.7.12
    appdirs: 1.4.4
    appnope: 0.1.0
    Babel: 2.8.0
    backcall: 0.2.0
    blockdiag: 2.0.1
    certifi: 2020.6.20
    chardet: 3.0.4
    ChimeraX-AddH: 2.1.3
    ChimeraX-AlignmentAlgorithms: 2.0
    ChimeraX-AlignmentHdrs: 3.2
    ChimeraX-AlignmentMatrices: 2.0
    ChimeraX-Alignments: 2.1
    ChimeraX-Arrays: 1.0
    ChimeraX-Atomic: 1.6.1
    ChimeraX-AtomSearch: 2.0
    ChimeraX-AxesPlanes: 2.0
    ChimeraX-BasicActions: 1.1
    ChimeraX-BILD: 1.0
    ChimeraX-BlastProtein: 1.0.1
    ChimeraX-BondRot: 2.0
    ChimeraX-BugReporter: 1.0
    ChimeraX-BuildStructure: 2.0
    ChimeraX-Bumps: 1.0
    ChimeraX-BundleBuilder: 1.0
    ChimeraX-ButtonPanel: 1.0
    ChimeraX-CageBuilder: 1.0
    ChimeraX-CellPack: 1.0
    ChimeraX-Centroids: 1.1
    ChimeraX-ChemGroup: 2.0
    ChimeraX-Clashes: 2.0
    ChimeraX-ColorActions: 1.0
    ChimeraX-ColorGlobe: 1.0
    ChimeraX-CommandLine: 1.1.3
    ChimeraX-ConnectStructure: 2.0
    ChimeraX-Contacts: 1.0
    ChimeraX-Core: 1.1.1
    ChimeraX-CoreFormats: 1.0
    ChimeraX-coulombic: 1.0.1
    ChimeraX-Crosslinks: 1.0
    ChimeraX-Crystal: 1.0
    ChimeraX-DataFormats: 1.0
    ChimeraX-Dicom: 1.0
    ChimeraX-DistMonitor: 1.1
    ChimeraX-DistUI: 1.0
    ChimeraX-Dssp: 2.0
    ChimeraX-EMDB-SFF: 1.0
    ChimeraX-ExperimentalCommands: 1.0
    ChimeraX-FileHistory: 1.0
    ChimeraX-FunctionKey: 1.0
    ChimeraX-Geometry: 1.1
    ChimeraX-gltf: 1.0
    ChimeraX-Graphics: 1.0
    ChimeraX-Hbonds: 2.0
    ChimeraX-Help: 1.0
    ChimeraX-HKCage: 1.3
    ChimeraX-IHM: 1.0
    ChimeraX-ImageFormats: 1.0
    ChimeraX-IMOD: 1.0
    ChimeraX-IO: 1.0
    ChimeraX-Label: 1.0
    ChimeraX-ListInfo: 1.0
    ChimeraX-Log: 1.1.1
    ChimeraX-LookingGlass: 1.1
    ChimeraX-Map: 1.0.1
    ChimeraX-MapData: 2.0
    ChimeraX-MapEraser: 1.0
    ChimeraX-MapFilter: 2.0
    ChimeraX-MapFit: 2.0
    ChimeraX-MapSeries: 2.0
    ChimeraX-Markers: 1.0
    ChimeraX-Mask: 1.0
    ChimeraX-MatchMaker: 1.1
    ChimeraX-MDcrds: 2.0
    ChimeraX-MedicalToolbar: 1.0.1
    ChimeraX-Meeting: 1.0
    ChimeraX-MLP: 1.0
    ChimeraX-mmCIF: 2.2
    ChimeraX-MMTF: 2.0
    ChimeraX-Modeller: 1.0
    ChimeraX-ModelPanel: 1.0
    ChimeraX-ModelSeries: 1.0
    ChimeraX-Mol2: 2.0
    ChimeraX-Morph: 1.0
    ChimeraX-MouseModes: 1.0
    ChimeraX-Movie: 1.0
    ChimeraX-Neuron: 1.0
    ChimeraX-Nucleotides: 2.0
    ChimeraX-OpenCommand: 1.2.1
    ChimeraX-PDB: 2.1
    ChimeraX-PDBBio: 1.0
    ChimeraX-PickBlobs: 1.0
    ChimeraX-Positions: 1.0
    ChimeraX-PresetMgr: 1.0
    ChimeraX-PubChem: 2.0
    ChimeraX-Read-Pbonds: 1.0
    ChimeraX-Registration: 1.1
    ChimeraX-RemoteControl: 1.0
    ChimeraX-ResidueFit: 1.0
    ChimeraX-RestServer: 1.0
    ChimeraX-RNALayout: 1.0
    ChimeraX-RotamerLibMgr: 2.0
    ChimeraX-RotamerLibsDunbrack: 2.0
    ChimeraX-RotamerLibsDynameomics: 2.0
    ChimeraX-RotamerLibsRichardson: 2.0
    ChimeraX-SaveCommand: 1.2
    ChimeraX-SchemeMgr: 1.0
    ChimeraX-SDF: 2.0
    ChimeraX-Segger: 1.0
    ChimeraX-Segment: 1.0
    ChimeraX-SeqView: 2.2
    ChimeraX-Shape: 1.0.1
    ChimeraX-Shell: 1.0
    ChimeraX-Shortcuts: 1.0
    ChimeraX-ShowAttr: 1.0
    ChimeraX-ShowSequences: 1.0
    ChimeraX-SideView: 1.0
    ChimeraX-Smiles: 2.0
    ChimeraX-SmoothLines: 1.0
    ChimeraX-SpaceNavigator: 1.0
    ChimeraX-StdCommands: 1.0.4
    ChimeraX-STL: 1.0
    ChimeraX-Storm: 1.0
    ChimeraX-Struts: 1.0
    ChimeraX-Surface: 1.0
    ChimeraX-SwapAA: 2.0
    ChimeraX-SwapRes: 2.0
    ChimeraX-TapeMeasure: 1.0
    ChimeraX-Test: 1.0
    ChimeraX-Toolbar: 1.0
    ChimeraX-ToolshedUtils: 1.0
    ChimeraX-Tug: 1.0
    ChimeraX-UI: 1.2.3
    ChimeraX-uniprot: 2.0
    ChimeraX-ViewDockX: 1.0
    ChimeraX-Vive: 1.1
    ChimeraX-VolumeMenu: 1.0
    ChimeraX-VTK: 1.0
    ChimeraX-WavefrontOBJ: 1.0
    ChimeraX-WebCam: 1.0
    ChimeraX-WebServices: 1.0
    ChimeraX-Zone: 1.0
    colorama: 0.4.3
    comtypes: 1.1.7
    cxservices: 1.0
    cycler: 0.10.0
    Cython: 0.29.20
    decorator: 4.4.2
    distlib: 0.3.1
    docutils: 0.16
    filelock: 3.0.12
    funcparserlib: 0.3.6
    grako: 3.16.5
    h5py: 2.10.0
    html2text: 2020.1.16
    idna: 2.10
    ihm: 0.16
    imagecodecs: 2020.5.30
    imagecodecs-lite: 2020.1.31
    imagesize: 1.2.0
    ipykernel: 5.3.0
    ipython: 7.15.0
    ipython-genutils: 0.2.0
    jedi: 0.17.2
    Jinja2: 2.11.2
    jupyter-client: 6.1.3
    jupyter-core: 4.6.3
    kiwisolver: 1.2.0
    line-profiler: 2.1.2
    lxml: 4.5.1
    MarkupSafe: 1.1.1
    matplotlib: 3.2.1
    msgpack: 1.0.0
    netifaces: 0.10.9
    networkx: 2.4
    numexpr: 2.7.1
    numpy: 1.18.5
    numpydoc: 1.0.0
    openvr: 1.12.501
    packaging: 20.4
    parso: 0.7.1
    pexpect: 4.8.0
    pickleshare: 0.7.5
    Pillow: 7.1.2
    pip: 20.2.2
    pkginfo: 1.5.0.1
    prompt-toolkit: 3.0.7
    psutil: 5.7.0
    ptyprocess: 0.6.0
    pycollada: 0.7.1
    pydicom: 2.0.0
    Pygments: 2.6.1
    PyOpenGL: 3.1.5
    PyOpenGL-accelerate: 3.1.5
    pyparsing: 2.4.7
    PyQt5-commercial: 5.12.3
    PyQt5-sip: 4.19.19
    PyQtWebEngine-commercial: 5.12.1
    python-dateutil: 2.8.1
    pytz: 2020.1
    pyzmq: 19.0.2
    qtconsole: 4.7.4
    QtPy: 1.9.0
    RandomWords: 0.3.0
    requests: 2.24.0
    scipy: 1.4.1
    setuptools: 49.4.0
    sfftk-rw: 0.6.6.dev0
    six: 1.15.0
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    sphinxcontrib-blockdiag: 2.0.0
    sphinxcontrib-devhelp: 1.0.2
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File attachment: DNA.pdb

DNA.pdb​

[yaohe@…]

Added by email2trac

[Eric Pettersen]

Hi Yao,

To fit a structure's sequence into the full sequence, Chimera(X) simply scans the structure sequence along the full sequence, looking for the position with the least mismatches. Well, it's more complicated than that because of possible missing areas in the middle of the structure, but in the case you're reporting it's exactly that. If there are multiple positions with the same lowest number of mismatches, it takes the first one.
Changing that code to accommodate looking at residue numbering would be pretty challenging, so my question is: how much is this affecting your work? Is there something you can't do because the structure is matching to the sequence in the wrong position?

--Eric

Eric Pettersen
UCSF Computer Graphics Lab

[yaohe@…]

Hi Eric,

Thanks for your quick response and explanation. The current
sequence doesn't affect any operation within Chimera(X), but might
introduce confusions.

The DNA coordinate attached in the last email is part of my structure,
which is a DNA polymerase. In the real caes, the DNA polymerase should bind
to the 3' end of the DNA chain (G30 in the structure) and elongate the DNA
chain from there. This is one of the key features of my structure. However,
the current sequence shown in Chimera(X) indicates that the polymerase
binds to a middle region of the DNA chain, since there are unmodeled
nucleotides beyond G30. I am afraid it will mislead people if they use
Chimera(X) to check my structure.

One way to avoid this bug is to remove the unmodeled nucleotides from PDB.
However, this is forbidden during PDB deposition, since I was asked to
upload the real sequence of DNA used in my sample.

I fully understand your hard work to maintain such a great program(s). I
hope this bug could be fixed when you or your colleagues are available.

Best regard,
Yao



On Mon, Mar 1, 2021 at 2:35 PM ChimeraX <ChimeraX-bugs-admin@cgl.ucsf.edu>
wrote:

[Eric Pettersen]

Thanks for the feedback -- it helps me prioritize this against other development needs.

--Eric