[ccp4bb] LECTURER/SENIOR LECTURER IN STRUCTURAL BIOLOGY

2011-04-06 Thread Aaron McGrath
Hi all, I have been asked to pass on the following details for a position at the University of Sydney. Please address all correspondence to the University of Sydney as detailed below. Cheers, Aaron LECTURER/SENIOR LECTURER IN STRUCTURAL BIOLOGY SCHOOL OF MOLECULAR BIOSCIENCE REFERENCE NO.

Re: [ccp4bb] diffraction of spherulites

2011-04-06 Thread Colin Nave
Stefan A second go! Can you compare the spacings of some of the rings, including the ones showing partial alignment, with the ones in this picture. http://www.pnas.org/content/102/2/315/F2.large.jpg PNAS January 11, 2005 vol. 102 no. 2 315-320 Molecular basis for amyloid fibril formation an

[ccp4bb] diffraction of spherulites

2011-04-06 Thread Colin Nave
I should point out that the reference I gave is quite misleading as the samples studied contained lecithin Apologies Colin > -Original Message- > From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of > Colin Nave > Sent: 06 April 2011 18:33 > To: CCP4BB@JISCMAIL.AC.UK >

[ccp4bb] Advanced motif searches of the PDB (was: disulfide bond question)

2011-04-06 Thread Gerard DVD Kleywegt
Hi all, The following question was posed on the CCP4 bulletin board earlier this week: I have a question related to protein structure, but not crystallography per se. Has anyone see a disulfide forming between the two cys of "CXC" in the middle of a loop, and create a sharp turn, where X is not

Re: [ccp4bb] **Possible spam**Re: [ccp4bb] FW: [ccp4bb] diffraction of spherulites

2011-04-06 Thread Colin Nave
First few reflections seem characteristic of lamellar (rather than 3D crystals). Might be something other than PEG but see Magda El Nokaly, Stig E. Friberg, David W. Larsen, Lyotropic liquid crystals from lecithin, water, and polyethylene glycol, Journal of Colloid and Interface Science, Volum

Re: [ccp4bb] FW: [ccp4bb] diffraction of spherulites

2011-04-06 Thread Jacob Keller
It seems hard to imagine what there is anything in his solutions other than protein that would make spherulites, no? PEG 8000 at 12% seems pretty benign, unless the trays or screens have been sitting around for quite a while... JPK On Wed, Apr 6, 2011 at 12:04 PM, Colin Nave wrote: > > > Stefan

[ccp4bb] FW: [ccp4bb] diffraction of spherulites

2011-04-06 Thread Colin Nave
Stefan Could the low angle reflections be from lamellar liquid crystals of the PEG (or a mixed PEG/water phase). Seems like you have 1st,2nd and 4th order reflections with presumably the 2nd order about 20A. I think 40A lamellar spacing is characteristic of some PEG liquid crystals. Colin From

Re: [ccp4bb] problem of conventions

2011-04-06 Thread Ian Tickle
Bernhard, > Well, "it" *IS* broke. As they say "it works for me", so either you're using a different set of programs from me, or you're using the same programs but in a different way. Perhaps you could be more specific as to which program(s) appear to be broken? If possible please post the logf

[ccp4bb] Twinning

2011-04-06 Thread kavya
Dear users, Is there a possibility that both non-merohedral twinning and partial hemihedral twinning occur in the same crystal? In one of the data in R3, sfcheck indicated twinning and thus upon using twinning option during refinement, refmac considered twinning operator of (k h -l). But the

Re: [ccp4bb] diffraction of spherulites

2011-04-06 Thread David Briggs
Hi Stefan, IIRC, a ring at 20Å means that one of the cell edges is at least 20Å long - which might be considered unusually long for a salt crystal - but it's also on the short side for a protein cell edge - how big is your protein? If there are rings at lower resolution, then maybe these longer e

Re: [ccp4bb] diffraction of spherulites

2011-04-06 Thread Stefan Münnich
Hi Dave, thanks for your reply. Is there any chance of telling whether it is salt or protein from the diffraction image? Stefan On Apr 6, 2011, at 12:16 PM, David Briggs wrote: > Hi Stefan, > > It looks like a powder diffraction-type image. > > http://en.wikipedia.org/wiki/Powder_diffracti

Re: [ccp4bb] diffraction of spherulites

2011-04-06 Thread David Briggs
Hi Stefan, It looks like a powder diffraction-type image. http://en.wikipedia.org/wiki/Powder_diffraction You can imagine that your spherulites are made up of many small crystals in random orientations, a bit like a powder - this means that rather than getting discrete diffraction spots as you w

[ccp4bb] diffraction of spherulites

2011-04-06 Thread Stefan Münnich
Hey guys, When I collect data from these spherulites/crystals (grown in 0.1 M sodium acetate, 0.1 M MOPS pH 7.5, 12 % (w/v) PEG-8000, protein buffer: 100 mM NaCl, 50 mM HEPES pH 7.5): http://img695.imageshack.us/i/cryst.png/ I get this diffraction pattern: (it's not cryo protected, so there's

Re: [ccp4bb] how to Collecting Data from Long Unit Cell Axes ?

2011-04-06 Thread Kay Diederichs
Dear all, of course this may not always be possible, but let me suggest that in cases such as this, the original poster should consider to make her dataset (or at least 10 degrees at phi=0, and another 10 degrees at phi=90) available (by FTP or from a webserver, or even using a publicly acces