Dear Chitra, Crystallizing both proteins together is a very good idea: If you get a structure, it will be an interesting one, even if the C-terminus remains invisible.
Concerning the flexible C-terminus: is it the linker linking the second domain to the first one? In that case it might just be a bait, attracting a protease to get the second domain chopped off. In that case, chances of getting it structured may be slim and if you get it structured, it might be a crystal packing artifact. However, as Klemens mentioned, you should nevertheless try! If this flexible C-terminus gets cleaved by a protease, you may also try to get some cocrystal structure with the protease. There are quite a few tricks available to achieve this. Best, Herman Von: chitra latka <[email protected]> Gesendet: Donnerstag, 12. März 2020 12:59 An: Schreuder, Herman /DE <[email protected]> Cc: [email protected] Betreff: Re: [EXTERNAL] [ccp4bb] Flexible C terminus EXTERNAL : Real sender is [email protected]<mailto:[email protected]> Dear Herman, Its a two domain protein and the second domain gets chopped off and stabilises the other domain by binding near the flexible C - terminus of first domain. I am trying to crystallise both the proteins together. Literature review doesn't report binding of the protein to any other protein. So, it kind of has the ligand or another domain to stabilise but eve then density of C-terminus residues remain missing. Thanks Chitra Latka On Thu, Mar 12, 2020 at 4:08 PM Schreuder, Herman /DE <[email protected]<mailto:[email protected]>> wrote: Dear Chitra, There usually is a reason the C-terminus is disordered. Either it needs to bind a ligand to get ordered, or it needs to bind to some other protein. You have to check the literature. If the C-terminus binds a ligand, you have to add this ligand to your crystallization experiment. If it binds to some other protein, you could try cocrystallization of both proteins, or just try to cocrystallize the other protein with only the 20 residues or so of the C-terminus. Best, Herman Von: CCP4 bulletin board <[email protected]<mailto:[email protected]>> Im Auftrag von chitra latka Gesendet: Donnerstag, 12. März 2020 08:54 An: [email protected]<mailto:[email protected]> Betreff: [EXTERNAL] [ccp4bb] Flexible C terminus EXTERNAL : Real sender is [email protected]<mailto:[email protected]> Dear All, I am working on a protein that has flexible C terminus. None of the available structures even in homologs have density for C term region (around 20 odd residues). All the available pdb entries have missing density for these 20 residues at C terminus. I am going to try my luck crystallising the entire protein in hope of getting density for C term residues as well (Fingers crossed). Has anyone faced a similar problem where they have managed to get density for a flexible terminus successfully? Any suggestions would be appreciated. Cheers ! Chitra Latka ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.jiscmail.ac.uk_cgi-2Dbin_webadmin-3FSUBED1-3DCCP4BB-26A-3D1&d=DwMFaQ&c=Dbf9zoswcQ-CRvvI7VX5j3HvibIuT3ZiarcKl5qtMPo&r=HK-CY_tL8CLLA93vdywyu3qI70R4H8oHzZyRHMQu1AQ&m=tHXRPIRekvSgMSDPEVP15ta2iH1g8NkqcZVMEpk1VLo&s=k0Yuiu6SCu5YkIBlnejKmh7Eq9F_cX3TLtdqQZVyR3w&e=> -- Regards Chitra ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
