Dear All,
I was trying to use Modeller to produce coordinates of parts of a given target sequence based on full PDB coordinates of a template. For example: my template has a sequence AAAAABBCCCCCDDEEEEE which represents three helices (AAAAA, CCCCC, EEEEE) connected by two loops (BB, DD). My target has a sequence aaaaabbcccccddeeeee (again three helices and two loops) and I would like to overlap target helices on the template helices such that the loops in target are ignored. In other words, the resulting coordinates for the target would just have three helices (aaaaa, ccccc, eeeee). I have tried different alignment variants, such as:
>P1;mol1 structureX:mol1:1: :19: : :2.2: AAAAABBCCCCCDDEEEEE*
>P1;mol2 sequence:mol2: : : : : : : aaaaa--ccccc--eeeee*
but the target sequence always wants to be connected; I don't know how to make Modeller to produce three helical fragments modeled on template helices of the full PDB structure. If some Modeller expert could provide advice or point out what I am doing wrong, I would greatly appreciate it...
Thanks! -Viktor
Viktor Hornak wrote: > I was trying to use Modeller to produce coordinates of parts of a given > target sequence based on full PDB coordinates of a template. > For example: my template has a sequence AAAAABBCCCCCDDEEEEE which > represents three helices (AAAAA, CCCCC, EEEEE) connected by two loops > (BB, DD). My target has a sequence aaaaabbcccccddeeeee (again three > helices and two loops) and I would like to overlap target helices on the > template helices such that the loops in target are ignored. In other > words, the resulting coordinates for the target would just have three > helices (aaaaa, ccccc, eeeee). I have tried different alignment > variants, such as: > > >P1;mol1 > structureX:mol1:1: :19: : :2.2: > AAAAABBCCCCCDDEEEEE* > > >P1;mol2 > sequence:mol2: : : : : : : > aaaaa--ccccc--eeeee* > > > but the target sequence always wants to be connected; I don't know how > to make Modeller to produce three helical fragments modeled on template > helices of the full PDB structure.
The sequence is connected because Modeller builds CHARMM stereochemical restraints on all atoms in a given chain, which include inter-residue backbone restraints. To get multiple fragments, just break the chain at the appropriate places by putting in chain break characters ('/'). So your alignment might look like
>P1;mol1 structureX:mol1:1: :19: : :2.2: AAAAABBCCCCCDDEEEEE*
>P1;mol2 sequence:mol2: : : : : : : aaaaa/-ccccc/-eeeee*
Ben Webb, Modeller Caretaker