Re: [ccp4bb] Unidentified electron density

2025-02-03 Thread Chris Fage
Thanks to everyone for the quick replies! I’ll start by fitting PEG and let you know how it goes. Best wishes, Chris On Mon, 3 Feb 2025 at 18:22 Boaz Shaanan wrote: > So it does to me too. There are a few PEG variants in the monomer library, > have you tried them? Most PEGs, if not all, are mi

Re: [ccp4bb] Unidentified electron density

2025-02-03 Thread Boaz Shaanan
So it does to me too. There are a few PEG variants in the monomer library, have you tried them? Most PEGs, if not all, are mixtures in terms of chain length. Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben Gurion University Beer Sheva, Israel On Feb 3, 2025 19:12, Dale Tronrud wrote: Looks l

Re: [ccp4bb] Unidentified electron density

2025-02-03 Thread Dale Tronrud
Looks like a pretty good PEG fragment to me. Dale Tronrud On 2/3/2025 8:42 AM, Chris Fage wrote: Dear All, Our ~2.3 Å crystal structure contains a tube of electron density for an unknown ligand, into which we've built a network of water molecules (see attached images with 2Fo-Fc map conto

Re: [ccp4bb] Unidentified electron density

2022-07-02 Thread Jon Cooper
Agreed, it doesn't look like a zinc site, or indeed any metal site, with all those basic residues around it, but just being a bad loser ;-0 Cheers, Jon.C. Sent from ProtonMail mobile Original Message On 2 Jul 2022, 08:14, Eleanor Dodson wrote: > Did you check anomalous differe

Re: [ccp4bb] Unidentified electron density

2022-07-02 Thread Eleanor Dodson
Did you check anomalous difference peaks? They would show zn very clearly. On Sat, 2 Jul 2022 at 08:08, Sayan Saha wrote: > Dear all, > As suggested by most people, we modeled Zn2+ ions coordinated with > three water molecules. > Thanks for everyone’s response. > > With best regards, > Sayan

Re: [ccp4bb] Unidentified electron density

2022-07-02 Thread Sayan Saha
Dear all, As suggested by most people, we modeled Zn2+ ions coordinated with three water molecules. Thanks for everyone’s response. With best regards, Sayan Saha On Fri, Jul 1, 2022 at 8:04 PM Jon Cooper wrote: > Hello, I wonder if it is disorder i.e. alternative conformations of the > Asp

Re: [ccp4bb] Unidentified electron density

2022-07-01 Thread Jon Cooper
Hello, I wonder if it is disorder i.e. alternative conformations of the Asp and flexible Lys. Do let us know your final interpretation as we don't often, or indeed ever, hear the final outcome of these mystery density competitions and I would love to learn more from them. Cheers, Jon.C. Sent

Re: [ccp4bb] Unidentified electron density

2022-06-30 Thread Mark J. van Raaij
Could it be Tris? Mark J van Raaij Dpto de Estructura de Macromoleculas, lab 20B Centro Nacional de Biotecnologia - CSIC calle Darwin 3 E-28049 Madrid, Spain tel. +34 91 585 4616 (internal 432092) Section Editor Acta Crystallographica F https://journals.iucr.org/f/ https://namedrop.io/markvanraa

Re: [ccp4bb] Unidentified electron density

2022-06-30 Thread David Briggs
riggs From: CCP4 bulletin board on behalf of Sayan Saha Sent: 30 June 2022 08:03 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Unidentified electron density External Sender: Use caution. Dear All, I am trying to refine a protein structure. I observed an additional ele

Re: [ccp4bb] Unidentified electron density

2022-06-30 Thread Harmer, Nicholas
ciate Professor in Structural Biochemistry University of Exeter Living Systems Institute Stocker Road Exeter EX4 4QD UK From: CCP4 bulletin board On Behalf Of Sayan Saha Sent: 30 June 2022 08:03 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Unidentified electron density CAUTION: This email originated

Re: [ccp4bb] unidentified electron density

2018-07-19 Thread Bernhard Rupp
, 2018 09:06 > To: CCP4BB@JISCMAIL.AC.UK > Subject: [ccp4bb] unidentified electron density > > Dear All > > I am refining a 1.63 Angstrom data set for a methyltransferase for > which methyl-accepting substrate is not known. I came across a density > in the putative substra

Re: [ccp4bb] unidentified electron density

2018-07-19 Thread Robbie Joosten
CP4BB@JISCMAIL.AC.UK > Subject: [ccp4bb] unidentified electron density > > Dear All > > I am refining a 1.63 Angstrom data set for a methyltransferase for which > methyl-accepting substrate is not known. I came across a density in the > putative substrate binding site in which i

Re: [ccp4bb] Unidentified electron density blob

2018-07-06 Thread Jan Stransky
CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of zaigham mahmood khan Sent: Friday, July 06, 2018 15:30 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Unidentified electron density blob Hey Uma Yes, you are right that PFPE is too big for this density. Also, more experienced scientist

Re: [ccp4bb] Unidentified electron density blob

2018-07-06 Thread Robbie Joosten
--Original Message- > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of > zaigham mahmood khan > Sent: Friday, July 06, 2018 15:30 > To: CCP4BB@JISCMAIL.AC.UK > Subject: Re: [ccp4bb] Unidentified electron density blob > > Hey Uma > > Yes, you ar

Re: [ccp4bb] Unidentified electron density blob

2018-07-06 Thread zaigham mahmood khan
Hey Uma Yes, you are right that PFPE is too big for this density. Also, more experienced scientist in this field has already commented on it. For the second part of your query, this is how one can generate the "crystallographic information file" - .cif for the ligand of choice (in case it is not

Re: [ccp4bb] Unidentified electron density blob

2018-07-06 Thread Wim Burmeister
Hello, a really molecule should show up also in the 2Fo-Fc type map. This appears not to be the case. So indeed it is likely that your density corresponds to some alternate conformation of the surrounding residues present with low occupancy. The glutamic acid sidechai

Re: [ccp4bb] Unidentified electron density blob

2018-07-03 Thread Uma Gabale
Thanks Zaighum, Artem, and Eleanor, for your replies. @Zaighum: I could not find a pdb file for PFPE- it is not listed in common ligand dictionaries of Refmac, Phenix or even HIC-Up server, or in general. It is fairly big molecule  to fit into this small cavity. Also I couldn't find any protein

Re: [ccp4bb] Unidentified electron density blob

2018-07-02 Thread Eleanor Dodson
Hmm - is the refinement complete? Maybe the GLU on the right could be moved to use some of that greenness? I try to make all sensible corrections, then check blobs.. Eleanor On 3 July 2018 at 04:22, zaigham mahmood khan wrote: > Uma, that is not something that we see regularly in the crystal > s

Re: [ccp4bb] Unidentified electron density blob

2018-07-02 Thread zaigham mahmood khan
Uma, that is not something that we see regularly in the crystal structures. But i never used PFPE either. So, you may try PFPE. If this is not PFPE, then you may read the biology of the protein. Also I can see green density, but these green blobs are devoid of blue density. So i will be cautious.