[ccp4bb] AW: [ccp4bb] Posting again: Is the H-bond length in CYS.cif library correct?

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

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Subject: Re: Posting again: Is the H-bond length in CYS.cif library correct?
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-08-20

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Subject: Re: Posting again: Is the H-bond length in CYS.cif library correct?
From: "George M {- dot -} Sheldrick" gsheldr {- at -} SHELX {- dot -} UNI-AC {- dot -} GWDG {- dot -} DE
Date: 2007-08-20

Subject: AW: Posting again: Is the H-bond length in CYS.cif library correct?
From: Herman {- dot -} Schreuder {- at -} SANOFI-AVENTIS {- dot -} COM Herman {- dot -} Schreuder {- at -} SANOFI-AVENTIS {- dot -} COM
Date: 2007-08-20

Dear Juergen,
I did a quick check in the CSD and found SG-H bondlengths between 0.587 and 1.338 Ang. for various cysteine derivatives. The most common values where around 1.33 Ang. but the average may be around 1.1 or 1.2 Ang. I did not work out any statistics. It seems that the SG-H distance is either experimentally not very well defined (there were quite a few entries with this hydrogen missing) or it might be very sensitive to e.g. (ionization).

I hope this helps.
Best regards,
Herman

-----Ursprüngliche Nachricht-----
Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Juergen J. Mueller
Gesendet: Montag, 20. August 2007 15:31
An: CCP4BB@JISCMAIL.AC.UK
Betreff: [ccp4bb] Posting again: Is the H-bond length in CYS.cif library correct?

Dear all,
using refmac5 to provide H-atoms for a known protein structure the distance between CYS-CG and HG is defined to 1.34 Ang. in CYS.cif.

This distance has been critisiced by a non-CCP4 program by
* Poor covalent bond length of 1.33954 for hydrogen atom HG.

In an other library-file CSH.cif the same distance is defined to 1.1 Ang.
WHATIF uses 1.0 Ang. What is the most correct one?
Could the CCP4-people comment on this?

(Of course I know hydrogens will not be refined but they are neccessary for some modeling programs).

Thank you,
Juergen

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

Previous message:
Subject: Re: Posting again: Is the H-bond length in CYS.cif library correct?
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-08-20