Difference between revisions of "2013 DOCK tutorial with Orotodine Monophosphate Decarboxylase"

Revision as of 14:00, 25 February 2013

For additional Rizzo Lab tutorials see DOCK Tutorials. Use this link Wiki Markup as a reference for editing the wiki. This tutorial was developed collaboratively by the AMS 536 class of 2012.

I. Introduction

DOCK

DOCK is a molecular docking program used in drug discovery. It was developed by Irwin D. Kuntz, Jr. and colleagues at UCSF (see UCSF DOCK). This program, given a protein binding site and a small molecule, tries to predict the correct binding mode of the small molecule in the binding site, and the associated binding energy. Small molecules with highly favorable binding energies could be new drug leads. This makes DOCK a valuable drug discovery tool. DOCK is typically used to screen massive libraries of millions of compounds against a protein to isolate potential drug leads. These leads are then further studied, and could eventually result in a new, marketable drug. DOCK works well as a screening procedure for generating leads, but is not currently as useful for optimization of those leads.

DOCK 6 uses an incremental construction algorithm called anchor and grow. It is described by a three-step process:

1. Rigid portion of ligand (anchor) is docked by geometric methods.
2. Non-rigid segments added in layers; energy minimized.
3. The resulting configurations are 'pruned' and energy re-minimized, yielding the docked configurations.

Orotodine Monophosphate Decarboxylase

The protein which is the subject of this tutorial is orotodine monophosphate decarboxylase (OMP), a homodimeric protein from the organism Methanobacterium thermoautotrophicum. OMP is involved in the biosynthesis of several pyrimidines including uridine monophosphate (UMP), the ligand used in this tutorial. UMP is a pyrimidine-based nucleotide monomer of RNA.

Organizing Directories

While performing docking, it is convenient to adopt a standard directory structure / naming scheme, so that files are easy to find / identify. For this tutorial, we will use something similar to the following:

~username/AMS536/DOCK-Tutorial/00.original-files/
                              /01.dockprep/
                              /02.surface-spheres/
                              /03.box-grid/
                              /04.dock/
                              /05.virtual-screen/

In addition, most of the important files that are derived from the original crystal structure will be given a prefix that is the same as the PDB code, '1LOQ'. The following sections in this tutorial will adhere to this directory structure / naming scheme.

II. Preparing the Receptor and Ligand

III. Generating Receptor Surface and Spheres

IV. Generating Box and Grid

V. Docking a Single Molecule for Pose Reproduction

Results

VI. Virtual Screening

VII. Running DOCK in Serial and in Parallel on Seawulf

VII. Frequently Encountered Problems