Hello, there's another one at 1.1 A in 5JK4 which was a contaminant that crystallised over 2 years. No mass-spec, though! Cheers, Jon.C.
http://scripts.iucr.org/cgi-bin/paper?S2059798316010433 Sent from ProtonMail mobile -------- Original Message -------- On 21 Apr 2021, 17:01, Isabel Moraes wrote: > Dear Jared, > > I advise you to have a look into our very recent Nat Comms paper (in > particular supplementary information) > https://doi.org/10.1038/s41467-020-20596-0 > > In our high-resolution crystal structures of the light-adapted (6S6C) and > dark-adapted (6GUX) state of Archaerhodopsin-3 (AR3), solved to 1.1 Å and 1.3 > Å > > respectively, the N-terminus residue Gln7 is modified to a pyroglutamyl group > (PCA). In our paper, we confirm this modification by native mass > spectroscopy. The AR3 protein was produce from its natural source and any > detergent was used during the purification or crystallisation processes. > Crystals were grown at pH5.5. > > I hope it helps > Isabel > > ------------------------------------------------------------------ > Isabel Moraes, PhD > Principal Research Scientist - Structural Biology > National Physical Laboratory (NPL) > > Hampton Rd | Teddington | Middlesex | TW11 0LW > ------------------------------------------------------------------- > > --------------------------------------------------------------- > > From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of Jared Sampson > <jared.samp...@columbia.edu> > Sent: 21 April 2021 16:15 > To: CCP4BB@JISCMAIL.AC.UK <CCP4BB@JISCMAIL.AC.UK> > Subject: [EXTERNAL] [ccp4bb] N-terminal PCA as artifact of crystallization? > > CAUTION: This email originated from outside of NPL. Do not click links or > open attachments unless you recognize the sender and know the content is safe. > > Dear all, > > I'm looking at a crystal structure (1H4G) where the N-terminal Glu residue > has cyclized to pyroglutamic acid (PCA). The protein was expressed in and > secreted from bacteria (Bacillus licheniformis), and the crystallization > conditions for 3 ul hanging drops were 2 ul protein solution (10 mg/ml in 100 > mM sodium acetate pH 6.0) + 1 ul reservoir solution (100 mM MES pH 6.5, 30% > ammonium sulphate). > > As I wouldn't typically expect this kind of post-translational modification > to appear in bacteria (please correct me if I'm mistaken about this), I > suspect the presence of PCA here to be an artifact of crystallization. > > Have others seen cyclization of N-terminal Glu or Gln to PCA under such > acidic crystallization conditions? I'd be interested in seeing any relevant > literature you might be able to suggest. > > Many thanks, > > Jared > > --------------------------------------------------------------- > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > > Visit the [NPL > website](https://www.npl.co.uk/?utm_source=Email%20Footer&utm_medium=email&utm_campaign=Homepage) > and find out how our cutting-edge measurement science has a positive impact > in the real world > > --------------------------------------------------------------- > > [https://www.npl.co.uk/](https://www.npl.co.uk/?utm_source=Email%20Footer&utm_medium=email&utm_campaign=Homepage) > [Keep in touch](https://www.npl.co.uk/contact) > http://www.twitter.com/npl http://www.facebook.com/npldigital > http://www.youtube.com/npldigital > --------------------------------------------------------------- > [NPL Privacy Policy](https://www.npl.co.uk/privacy-policy/) > > If you have received this message in error, please notify us and remove it > from your system. > NPL Management Ltd cannot guarantee that the e-mail or any attachments are > free from viruses. > > NPL Management Ltd is a company registered in England and Wales, number: > 2937881 > Registered office: National Physical Laboratory | Hampton Road | Teddington, > Middlesex | UK | TW11 0LW > > --------------------------------------------------------------- > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
