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{
  "nbformat": 4,
  "nbformat_minor": 0,
  "metadata": {
    "colab": {
      "name": "AlphaFold_single.ipynb",
      "provenance": [],
      "include_colab_link": true
    },
    "kernelspec": {
      "name": "python3",
      "display_name": "Python 3"
    },
    "language_info": {
      "name": "python"
    },
    "accelerator": "GPU"
  },
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "view-in-github",
        "colab_type": "text"
      },
      "source": [
        "<a href=\"https://colab.research.google.com/github/sokrypton/af_backprop/blob/beta/examples/AlphaFold_single.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "#AlphaFold - single sequence input\n",
        "- WARNING - For DEMO and educational purposes only. \n",
        "- For natural proteins you often need more than a single sequence to accurately predict the structure. See [ColabFold](https://colab.research.google.com/github/sokrypton/ColabFold/blob/main/AlphaFold2.ipynb) notebook if you want to predict the protein structure from a multiple-sequence-alignment. That being said, this notebook could potentially be useful for evaluating *de novo* designed proteins.\n"
      ],
      "metadata": {
        "id": "VpfCw7IzVHXv"
      }
    },
    {
      "cell_type": "code",
      "source": [
        "#@title Setup\n",
        "from IPython.utils import io\n",
        "import os,sys,re\n",
        "import tensorflow as tf\n",
        "import jax\n",
        "import jax.numpy as jnp\n",
        "import numpy as np\n",
        "\n",
        "with io.capture_output() as captured:\n",
        "  if not os.path.isdir(\"af_backprop\"):\n",
        "    %shell git clone -b beta https://github.com/sokrypton/af_backprop.git\n",
        "    %shell pip -q install biopython dm-haiku ml-collections py3Dmol\n",
        "    %shell wget -qnc https://raw.githubusercontent.com/sokrypton/ColabFold/main/beta/colabfold.py\n",
        "  if not os.path.isdir(\"params\"):\n",
        "    %shell mkdir params\n",
        "    %shell curl -fsSL https://storage.googleapis.com/alphafold/alphafold_params_2021-07-14.tar | tar x -C params\n",
        "\n",
        "try:\n",
        "  # check if TPU is available\n",
        "  import jax.tools.colab_tpu\n",
        "  jax.tools.colab_tpu.setup_tpu()\n",
        "  print('Running on TPU')\n",
        "  DEVICE = \"tpu\"\n",
        "except:\n",
        "  if jax.local_devices()[0].platform == 'cpu':\n",
        "    print(\"WARNING: no GPU detected, will be using CPU\")\n",
        "    DEVICE = \"cpu\"\n",
        "  else:\n",
        "    print('Running on GPU')\n",
        "    DEVICE = \"gpu\"\n",
        "    # disable GPU on tensorflow\n",
        "    tf.config.set_visible_devices([], 'GPU')\n",
        "\n",
        "sys.path.append('/content/af_backprop')\n",
        "# import libraries\n",
        "from utils import update_seq, update_aatype, get_plddt, get_pae\n",
        "import colabfold as cf\n",
        "from alphafold.common import protein\n",
        "from alphafold.data import pipeline\n",
        "from alphafold.model import data, config, model\n",
        "from alphafold.common import residue_constants\n",
        "\n",
        "def clear_mem():\n",
        "  backend = jax.lib.xla_bridge.get_backend()\n",
        "  for buf in backend.live_buffers(): buf.delete()\n",
        "\n",
        "def setup_model(max_len, model_name=\"model_2_ptm\"):\n",
        "\n",
        "  clear_mem()\n",
        "\n",
        "  # setup model\n",
        "  cfg = config.model_config(\"model_5_ptm\")\n",
        "  cfg.model.num_recycle = 0\n",
        "  cfg.data.common.num_recycle = 0\n",
        "  cfg.data.eval.max_msa_clusters = 1\n",
        "  cfg.data.common.max_extra_msa = 1\n",
        "  cfg.data.eval.masked_msa_replace_fraction = 0\n",
        "  cfg.model.global_config.subbatch_size = None\n",
        "  model_params = data.get_model_haiku_params(model_name=model_name, data_dir=\".\")\n",
        "  model_runner = model.RunModel(cfg, model_params, is_training=False)\n",
        "\n",
        "  seq = \"A\" * max_len\n",
        "  length = len(seq)\n",
        "  feature_dict = {\n",
        "      **pipeline.make_sequence_features(sequence=seq, description=\"none\", num_res=length),\n",
        "      **pipeline.make_msa_features(msas=[[seq]], deletion_matrices=[[[0]*length]])\n",
        "  }\n",
        "  inputs = model_runner.process_features(feature_dict,random_seed=0)\n",
        "\n",
        "  def runner(seq, opt):\n",
        "    # update sequence\n",
        "    inputs = opt[\"inputs\"]\n",
        "    inputs.update(opt[\"prev\"])\n",
        "    update_seq(seq, inputs)\n",
        "    update_aatype(inputs[\"target_feat\"][...,1:], inputs)\n",
        "\n",
        "    # mask prediction\n",
        "    mask = seq.sum(-1)\n",
        "    inputs[\"seq_mask\"] = inputs[\"seq_mask\"].at[:].set(mask)\n",
        "    inputs[\"msa_mask\"] = inputs[\"msa_mask\"].at[:].set(mask)\n",
        "    inputs[\"residue_index\"] = jnp.where(mask==1,inputs[\"residue_index\"],0)\n",
        "\n",
        "    # get prediction\n",
        "    key = jax.random.PRNGKey(0)\n",
        "    outputs = model_runner.apply(opt[\"params\"], key, inputs)\n",
        "\n",
        "    prev = {\"init_msa_first_row\":outputs['representations']['msa_first_row'][None],\n",
        "            \"init_pair\":outputs['representations']['pair'][None],\n",
        "            \"init_pos\":outputs['structure_module']['final_atom_positions'][None]}\n",
        "    \n",
        "    aux = {\"final_atom_positions\":outputs[\"structure_module\"][\"final_atom_positions\"],\n",
        "          \"final_atom_mask\":outputs[\"structure_module\"][\"final_atom_mask\"],\n",
        "          \"plddt\":get_plddt(outputs),\"pae\":get_pae(outputs),\n",
        "          \"inputs\":inputs, \"prev\":prev}\n",
        "    return aux\n",
        "\n",
        "  return jax.jit(runner), {\"inputs\":inputs,\"params\":model_params}\n",
        "\n",
        "MAX_LEN = 50\n",
        "RUNNER, OPT = setup_model(MAX_LEN)"
      ],
      "metadata": {
        "cellView": "form",
        "id": "24ybo88aBiSU"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "source": [
        "%%time\n",
        "#@title Enter the amino acid sequence to fold ⬇️\n",
        "\n",
        "sequence = 'GGGGGGGGGGGGGGGGGGGG' #@param {type:\"string\"}\n",
        "recycles = 0 #@param [\"0\", \"1\", \"2\", \"3\", \"6\", \"12\", \"24\"] {type:\"raw\"}\n",
        "SEQ = re.sub(\"[^A-Z]\", \"\", sequence.upper())\n",
        "LEN = len(SEQ)\n",
        "if LEN > MAX_LEN:\n",
        "  print(\"recompiling...\")\n",
        "  MAX_LEN = LEN\n",
        "  RUNNER, OPT = setup_model(MAX_LEN)\n",
        "\n",
        "x = np.array([residue_constants.restype_order.get(aa,0) for aa in SEQ])\n",
        "x = np.pad(x,[0,MAX_LEN-LEN],constant_values=-1)\n",
        "x = jax.nn.one_hot(x,20)\n",
        "\n",
        "OPT[\"prev\"] = {'init_msa_first_row': np.zeros([1, MAX_LEN, 256]),\n",
        "               'init_pair': np.zeros([1, MAX_LEN, MAX_LEN, 128]),\n",
        "               'init_pos': np.zeros([1, MAX_LEN, 37, 3])}\n",
        "\n",
        "positions = []\n",
        "plddts = []\n",
        "for r in range(recycles+1):\n",
        "  outs = RUNNER(x, OPT)\n",
        "  outs = jax.tree_map(lambda x:np.asarray(x), outs)\n",
        "  positions.append(outs[\"prev\"][\"init_pos\"][0,:LEN])\n",
        "  plddts.append(outs[\"plddt\"][:LEN])\n",
        "  OPT[\"prev\"] = outs[\"prev\"]\n",
        "  if recycles > 0:\n",
        "    print(r, plddts[-1].mean())"
      ],
      "metadata": {
        "cellView": "form",
        "id": "cAoC4ar8G7ZH"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "source": [
        "#@title Display 3D structure {run: \"auto\"}\n",
        "color = \"lDDT\" #@param [\"chain\", \"lDDT\", \"rainbow\"]\n",
        "show_sidechains = True #@param {type:\"boolean\"}\n",
        "show_mainchains = False #@param {type:\"boolean\"}\n",
        "#@markdown - TIP - hold mouse over aminoacid to get name and position number\n",
        "\n",
        "def save_pdb(outs, filename):\n",
        "  '''save pdb coordinates'''\n",
        "  p = {\"residue_index\":outs[\"inputs\"][\"residue_index\"][0][:LEN] + 1,\n",
        "        \"aatype\":outs[\"inputs\"][\"aatype\"].argmax(-1)[0][:LEN],\n",
        "        \"atom_positions\":outs[\"final_atom_positions\"][:LEN],\n",
        "        \"atom_mask\":outs[\"final_atom_mask\"][:LEN]}\n",
        "  b_factors = 100.0 * outs[\"plddt\"][:LEN,None] * p[\"atom_mask\"]\n",
        "  p = protein.Protein(**p,b_factors=b_factors)\n",
        "  pdb_lines = protein.to_pdb(p)\n",
        "  with open(filename, 'w') as f:\n",
        "    f.write(pdb_lines)\n",
        "\n",
        "save_pdb(outs,\"out.pdb\")\n",
        "num_res = int(outs[\"inputs\"][\"aatype\"][0].sum())\n",
        "\n",
        "v = cf.show_pdb(\"out.pdb\", show_sidechains, show_mainchains, color,\n",
        "                color_HP=True, size=(800,480))       \n",
        "v.setHoverable({},\n",
        "               True,\n",
        "               '''function(atom,viewer,event,container){if(!atom.label){atom.label=viewer.addLabel(\"      \"+atom.resn+\":\"+atom.resi,{position:atom,backgroundColor:'mintcream',fontColor:'black'});}}''',\n",
        "               '''function(atom,viewer){if(atom.label){viewer.removeLabel(atom.label);delete atom.label;}}''')\n",
        "v.show()           \n",
        "\n",
        "if color == \"lDDT\":\n",
        "  cf.plot_plddt_legend().show()  \n",
        "if \"pae\" in outs:\n",
        "  cf.plot_confidence(outs[\"plddt\"][:LEN]*100, outs[\"pae\"][:LEN,:LEN]).show()\n",
        "else:\n",
        "  cf.plot_confidence(outs[\"plddt\"][:LEN]*100).show()"
      ],
      "metadata": {
        "cellView": "form",
        "id": "-KbUGG4ZOp0J"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "source": [
        "#@title Animate\n",
        "#@markdown - Animate trajectory if more than 0 recycle(s)\n",
        "import matplotlib\n",
        "from matplotlib import animation\n",
        "import matplotlib.pyplot as plt\n",
        "from IPython.display import HTML\n",
        "\n",
        "def make_animation(positions, plddts=None, line_w=2.0):\n",
        "\n",
        "  def ca_align_to_last(positions):\n",
        "    def align(P, Q):\n",
        "      p = P - P.mean(0,keepdims=True)\n",
        "      q = Q - Q.mean(0,keepdims=True)\n",
        "      return p @ cf.kabsch(p,q)\n",
        "    \n",
        "    pos = positions[-1,:,1,:] - positions[-1,:,1,:].mean(0,keepdims=True)\n",
        "    best_2D_view = pos @ cf.kabsch(pos,pos,return_v=True)\n",
        "\n",
        "    new_positions = []\n",
        "    for i in range(len(positions)):\n",
        "      new_positions.append(align(positions[i,:,1,:],best_2D_view))\n",
        "    return np.asarray(new_positions)\n",
        "\n",
        "  # align all to last recycle\n",
        "  pos = ca_align_to_last(positions)\n",
        "\n",
        "  fig, (ax1, ax2, ax3) = plt.subplots(1,3)\n",
        "  fig.subplots_adjust(top = 0.90, bottom = 0.10, right = 1, left = 0, hspace = 0, wspace = 0)\n",
        "  fig.set_figwidth(13)\n",
        "  fig.set_figheight(5)\n",
        "  fig.set_dpi(100)\n",
        "\n",
        "  xy_min = pos[...,:2].min() - 1\n",
        "  xy_max = pos[...,:2].max() + 1\n",
        "\n",
        "  for ax in [ax1,ax3]:\n",
        "    ax.set_xlim(xy_min, xy_max)\n",
        "    ax.set_ylim(xy_min, xy_max)\n",
        "    ax.axis(False)\n",
        "\n",
        "  ims=[]\n",
        "  for k,(xyz,plddt) in enumerate(zip(pos,plddts)):\n",
        "    ims.append([])\n",
        "    im2 = ax2.plot(plddt, animated=True, color=\"black\")\n",
        "    tt1 = cf.add_text(\"colored by N->C\", ax1)\n",
        "    tt2 = cf.add_text(f\"recycle={k}\", ax2)\n",
        "    tt3 = cf.add_text(f\"pLDDT={plddt.mean():.3f}\", ax3)\n",
        "    ax2.set_xlabel(\"positions\")\n",
        "    ax2.set_ylabel(\"pLDDT\")\n",
        "    ax2.set_ylim(0,100)\n",
        "    ims[-1] += [cf.plot_pseudo_3D(xyz, ax=ax1, line_w=line_w)]\n",
        "    ims[-1] += [im2[0],tt1,tt2,tt3]\n",
        "    ims[-1] += [cf.plot_pseudo_3D(xyz, c=plddt, cmin=50, cmax=90, ax=ax3, line_w=line_w)]\n",
        "    \n",
        "  ani = animation.ArtistAnimation(fig, ims, blit=True, interval=120)\n",
        "  plt.close()\n",
        "  return ani.to_html5_video()\n",
        "\n",
        "HTML(make_animation(np.asarray(positions),\n",
        "                    np.asarray(plddts) * 100.0))"
      ],
      "metadata": {
        "cellView": "form",
        "id": "tdjdC0KFPjWw"
      },
      "execution_count": null,
      "outputs": []
    }
  ]
}