[ccp4bb] Postdoctoral position in cryoEM at KU Leuven (Belgium)

2023-05-04 Thread Sergei Strelkov
of Brussels. Laboratory for Biocrystallography, led by Prof. Sergei Strelkov, is active in structural biology and rational drug design. The working language is English. In addition to superb facilities for molecular biology and X-ray crystallography, there are two brand-new 200kV cryoelecton microscopes

Re: [ccp4bb] Synergy-R vs Synergy-S

2022-01-28 Thread Sergei Strelkov
Dear Wu, Just as you say there is an order of magnitude difference in intensity (one is a sealed tube and another is a rotating anode). Our experience with MicroMax007 is that it is often possible to collect a full dataset from a medium-sized crystal overnight. With a sealed tube, this would

[ccp4bb] Characterising potential drug-binding pockets

2021-01-25 Thread Sergei Strelkov
Dear everyone, In a drug discovery project where our aim is to interfere with some PPIs, we could obtain binding of drug-like fragments in several potentially interesting pockets on our target. We would like to make a projection on how promising these individual pockets are. One way of doing

Re: [ccp4bb] microscope camera

2019-11-28 Thread Sergei Strelkov
Moticam 5 has been working well for us for a few years now (installed on a Leica binocular) Prof. Sergei V. Strelkov Laboratory for Biocrystallography Department of Pharmaceutical Sciences, KU Leuven O, Campus Gasthuisberg, Herestraat 49 bus 822, 3000 Leuven, Belgium Phone: +32 16 33 08 45,

Re: [ccp4bb] coiled coil molecular replacement - PS

2019-10-08 Thread Sergei Strelkov
d Strelkov paper cited above. Sergei From: CCP4 bulletin board on behalf of Sergei Strelkov Sent: Tuesday, October 8, 2019 14:14 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] coiled coil molecular replacement Dear Tommi, With coiled coils you cert

Re: [ccp4bb] coiled coil molecular replacement

2019-10-08 Thread Sergei Strelkov
Dear Tommi, With coiled coils you certainly want to use the best search model possible. Coiled coils are elongated structures and a small local inaccuracy of your search model may result in large differences (in terms of overall rmsd) with respect to the true structure. Two suggestions: 1.

Re: [ccp4bb] design specs/tolerances for crystallization rooms?

2019-09-26 Thread Sergei Strelkov
Dear Frank and everyone, Thanks for useful tips. Snow in liquid nitrogen has been annoying us on a regular basis in fact. During some synchrotron sessions, a large percentage of crystals were covered with snow. We could never fully figure out how to get rid of it, although filtering LN2

Re: [ccp4bb] MR for coiled coil structure

2019-07-11 Thread Sergei Strelkov
Dear Shengyuang, Some further suggestions. To create a model towards MR searches, you could try our server for modelling coiled coils: https://pharm.kuleuven.be/apps/biocryst/ccfold.php It takes a few seconds to run. The reference is here: https://www.ncbi.nlm.nih.gov/pubmed/28968723 I

Re: [ccp4bb] Fo-Fc density close to cysteine residue

2019-07-10 Thread Sergei Strelkov
Dear Lumbini, Certainly not a proof but your density looks like (di)methyl-arsinoyl-cysteine (PDB residue type CAF). This modification can happen when the protein has been exposed to cacodylate buffer. You can find such residues (and maps) in the PDB entries 3LPT or 5MDI. Best wishes,

Re: [ccp4bb] Interesting pattern on a crystallization drop

2019-03-28 Thread Sergei Strelkov
Artem (and Beatriz), Me bad, could have thought about that! I think you are right. There were initially bubbles in each drop (7 in one case, 4 in the other). At some point the bubbles exploded (it was an instantaneous process, not just shrinking). Kind regards, Sergei Prof. Sergei V.

Re: [ccp4bb] Should we still keep copies of all raw data?

2018-07-13 Thread Sergei Strelkov
Department of Pharmaceutical Sciences, KU Leuven <http://pharm.kuleuven.be/anafar> From: John R Helliwell Sent: Friday, July 13, 2018 12:07 To: Sergei Strelkov Cc: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Should we still keep copies of all raw data?

[ccp4bb] Should we still keep copies of all raw data?

2018-07-13 Thread Sergei Strelkov
Dear All, I believe this question may be of some interest. In the past, we always stored all raw data ever collected by the lab. With the recent advances, such as (a) automated/on-the-fly processing offered by some (European) synchrotrons, and (b) an ongoing discussion on centralized raw

[ccp4bb] Postdoctoral opening in structural biology (protein crystallography and drug discovery) at KU Leuven, Belgium

2017-08-14 Thread Sergei Strelkov
Postdoctoral opening in structural biology (protein crystallography and drug discovery) at KU Leuven, Belgium There is an opening for a PhD level structural biologist (postdoc / senior postdoc) in my laboratory (http://pharm.kuleuven.be/Biocrystallography). KU Leuven, ranked the 35th best

[ccp4bb] Retired Rigaku RU-H2R system

2014-08-05 Thread Sergei Strelkov
We are about to recycle an old Rigaku RU-H2R rotating anode system (Cu anode, Yale mirrors). In case anyone is interested in some parts, please contact me as soon as possible. Regards, Sergei -- Prof. Sergei V. Strelkov Laboratory for Biocrystallography Dept of Pharmaceutical and

Re: [ccp4bb] Advice on setting up / maintaining a Ubuntu cluster

2013-08-08 Thread Sergei Strelkov
I wanted to thank everyone who responded, for a whole bunch of advice and suggestions! Sergei On 29-Jul-13 12:22 PM, Sergei Strelkov wrote: Dear all, In old times I, just like about any protein crystallographer, used to work on a cluster of SGI/IRIX workstations with complete NFS-based

[ccp4bb] Advice on setting up / maintaining a Ubuntu cluster

2013-07-29 Thread Sergei Strelkov
Dear all, In old times I, just like about any protein crystallographer, used to work on a cluster of SGI/IRIX workstations with complete NFS-based cross-mounting of hard disks. A typical operation included: 1. A single home directory location for every user: if my home directory was on

Re: [ccp4bb] Detwin

2012-12-10 Thread Sergei Strelkov
Dear Careina, Could you please let us know what your cell parameters are? And what is the twin law ('transformation') that you suspect? Best wishes, Sergei Dear CCP4 I have data that is twinned with an L statistic of 0.43. It seems all the crystals that I produced were twinned sadly. Is

Re: [ccp4bb] asking for a reference for cacodylate decomposition in protein crystals upon X-ray exposure

2012-07-30 Thread Sergei Strelkov
Dear Tatyana, We once had a project where the crystallization condition contained cacodylate. The crystals diffracted to 1.9A and survived reasonably well under the beam (maybe there was indeed some colour change upon exposure, I do not remember exactly). We were working with drug soaks. The

Re: [ccp4bb] MR - small coiled coil, 1.65A = 1.000 solutions, all of them wrong

2011-11-04 Thread Sergei Strelkov
(and it takes a lot of time for Phaser to run). Automated approaches also did not yield a better result (as far as I can tell). I'm convinced that the space group is C2221, but I may be wrong. Thanks to Sergei Strelkov for the numerous useful suggestions on how to approach the problem. One

Re: [ccp4bb] MR - small coiled coil, 1.65A = 1.000 solutions, all of them wrong

2011-10-19 Thread Sergei Strelkov
Dear Napoleão, I will try to summarize our experience and give some suggestions. Few reasons why MR with coiled coils can be very tricky, such as their asymmetric shape and their ability to overlap onto themselves upon a shift and rotation (for a heptad-based coiled coil, this would be a shift

[ccp4bb] Postdoctoral Position in Structural Bioinformatics at the University of Leuven, Belgium

2011-08-01 Thread Sergei Strelkov
a recommendation) to Prof. Sergei Strelkov, preferably before August 7, 2011. Applications from highly experienced candidates with previous postdoctoral experience and excellent track record are particularly welcome. Selected publications: Kuehnel K et al (2004) The VASP tetramerisation domain

Re: [ccp4bb] SFCHECK produces incomplete postscript

2011-04-01 Thread Sergei Strelkov
April 1st, 2011 Dear Andy, We have observed the same problem before, and just today we could finally find an explanation. Apparently, a new (still undocumented) functionality was quietly introduced into few widely used oscillation data processing programs, enabling the recording of the

Re: [ccp4bb] while on the subject of stereo

2011-03-03 Thread Sergei Strelkov
Dear Dave, Here come my five pence... I personally found stereo graphics useful in two cases. 1. When you first introduce students to biomolecular structure and/or biocrystallography. Showing stereo certainly helps 'building up' the initial fascination, which is very important of course. But

Re: [ccp4bb] helix translation

2010-12-06 Thread Sergei Strelkov
Dear Young-Tae, The program Twister (Strelkov and Burkhard, 2002) can calculate this, among other things. If you are interested I would gladly send you the program. Of course one should look into the reason for your helix having an aberrant geometry. If it is just a slightly distorted a-helix

Re: [ccp4bb] High Rmerge with thin frames

2010-11-06 Thread Sergei Strelkov
Dear All, first of all, I would like to thank the many good people who have responded to my query. Yet another truly interesting discussion on this BB! As a partial summary, two points: 1. Few people suggested that our high Rmerge problem could be caused by experimental troubles like phi angle

[ccp4bb] High Rmerge with thin frames

2010-11-05 Thread Sergei Strelkov
Dear All, I am processing a dataset collected (not by me) with 0.1 degree oscillations. The diffraction is quite weak even though there is a clean diffraction pattern to about 3A. Either Mosflm or XDS processes the data readily with +/- default settings but both yield a high overall Rmerge

Re: [ccp4bb] coiled coil question

2009-10-04 Thread Sergei Strelkov
Dear all,  Is anyone aware of a structure where the individual alpha helical chains of a coiled coil are related by a crystallographic axis? Or does anyone know of a coiled coil structure (dimer or higher order oligomer) that is perfectly symmetric at least in

[ccp4bb] In-house X-ray systems: what is your experience

2009-02-27 Thread Sergei Strelkov
who have recently considered or bought such systems could express their opinions with regard to few points, including (1) true intensity, (2) reliability, (3) ease of service such as alignment, filament chance, anode rebuild... I will post a summary afterwards. Many thanks in advance! Sergei Strelkov

[ccp4bb] Vacancy posting: PhD student position in structural biology / protein crystallography

2008-06-16 Thread Sergei Strelkov
be negotiated.  Please address any further questions and/or your application, including a detailed CV, publication list and a list of referees, to Prof. Sergei Strelkov via e-mail. Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm for more information.

[ccp4bb] Job advert: Postdoctoral and PhD student posts at the University of Leuven, Belgium

2007-07-25 Thread Sergei Strelkov
1. A postdoctoral position is available to work with Prof. Sergei Strelkov in the Laboratory for Biocrystallography, Department of Pharmaceutical Sciences, Catholic University of Leuven. The successful candidate should have considerable experience in protein crystallography, especially

Re: [ccp4bb] Program to 'visualize' the reciprocal space ?

2007-07-12 Thread Sergei Strelkov
of a program that would convert standard oscillation data (one-degree frames, mar225) into such a map? What we need is a direct conversion. There is a program in CCP4 that is able to 'visualize' the reciprocal space, but it requires hkl's as input. Thank you, Sergei Strelkov -- Prof. Sergei V