Re: [ccp4bb] cns and refmac refinement

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Subject: Aurigene Crystallography requirement
From: Ramesh Sistla ramesh_s {- at -} AURIGENE {- dot -} COM
Date: 2008-02-21

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Subject: Re: cns and refmac refinement
From: Anastassis Perrakis a {- dot -} perrakis {- at -} NKI {- dot -} NL
Date: 2008-02-21

Dear Yang Li,

On Feb 21, 2008, at 8:23, yang li wrote:

> Dear All,
> I have a 3A structure, the quality of the data is not very good.

I will stick a bit on your opening statement.

Having 3.0 A data is sometimes a fact of life - most unfortunately.
Sometimes, you simply cant do better with the crystals.

However, there is less excuse having bad data at 3.0 A.

In fact, i think, the best way to get away with 3.0 data in
refinement is to put a lot
of effort getting the best possible dataset out of your 3.0 A
crystals. 100% complete,
as redundant as possible, nice Rmerge, what you can.

If I look at the rest of your email now, I would think (based on how
much "not very good" your data is)
that either

1. You need a lot of manual rebuilding (was that molrep or madsad ?)
2. You need better quality data

From the Rfree going back up I would be quite worried.

As Pavel said though, his nice phenix.refine line (can we put it on
the wiki Pavel ?) is worth a shot first ;-)

A.

CCP4bb navigation

CCP4bb <-- 2008 <-- February 2008 <-- 21 February 2008

Previous message:
Subject: Aurigene Crystallography requirement
From: Ramesh Sistla ramesh_s {- at -} AURIGENE {- dot -} COM
Date: 2008-02-21

Next message:
Subject: Tough Low-Res MR
From: James Stroud jstroud {- at -} MBI {- dot -} UCLA {- dot -} EDU
Date: 2008-02-21