[ccp4bb] Solving structure of protein-protein complexes using MR

- Protein crystallography

Main steps:

- Protein purification
- Crystallisation

Special:

- Programs for crystallography
- X-ray detectors

Basic tutorials:

   - Chemistry
   - Protein
   - Peptide
   - Amino Acids

Xtal community:

- CCP4BB

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: How to replace 2.45M K/Na phosphate buffer - SUMMARY
From: Claudia Scotti claudiascotti {- at -} HOTMAIL {- dot -} COM
Date: 2007-07-06

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Subject: Re: Solving structure of protein-protein complexes using MR
From: "Manfred S {- dot -} Weiss" msweiss {- at -} EMBL-HAMBURG {- dot -} DE
Date: 2007-07-06

Subject: Solving structure of protein-protein complexes using MR
From: Joe Smith ewaldxray {- at -} GMAIL {- dot -} COM
Date: 2007-07-06

Hi all,

We have been trying to solve a structure of protein-protein complexes using
3.1A data (one of the proteins is of 120kDa whereas the other is of 20kDa).
The structure of smaller protein is known (individually-100% sequence
identity) whereas the bigger protein does not share more than 10% sequence
identity with the similar proteins solved from other sources.

Due to some problem in getting Seleno-labelled protein, we have also been
trying to use molecular replacement (MR) to solve the structure. We want to
find out the correct position of smaller protein using MR and then plan to
extend the phases to the whole asymmetric unit (we hope it could be done but
not sure). We are more or less sure about the fold of bigger protein and
expect it to be similar to the other known related structures.
In one of the solution obtained using phaser, the map looks really good, but
this solution doesn't provide good packing of the complex inside the unit
cell. Due to low scattering contribution of the smaller protein, we are
unable to refine any possible solutions using REFMAC.

We welcome any kind of suggestions in this regard.

Thanking you in advance.

Joe

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: How to replace 2.45M K/Na phosphate buffer - SUMMARY
From: Claudia Scotti claudiascotti {- at -} HOTMAIL {- dot -} COM
Date: 2007-07-06

Next message:
Subject: Re: Solving structure of protein-protein complexes using MR
From: "Manfred S {- dot -} Weiss" msweiss {- at -} EMBL-HAMBURG {- dot -} DE
Date: 2007-07-06