There's no theoretical reason it can't be that long. BUT it is possible, especially for problematic diffraction patterns (e.g. from a badly-diffracting, cracked crystal) for the software to pick some wacky value in its attempt to fit spots that don't really all belong in the same pattern.
You should be able to tell by looking at the images - are there rows of spots regularly spaced 1/652 A apart? Phoebe ---- Original message ---- >Date: Tue, 3 Aug 2010 10:27:34 -0400 >From: Matthew Franklin <matthew.frank...@imclone.com> >Subject: Re: [ccp4bb] Extremely long c-axis...reasonable? >To: CCP4BB@JISCMAIL.AC.UK > >Hi Christian - > >As a number of others have pointed out, this unit cell is unusual, but not impossible. It is, in fact, possible to search the PDB for unit cell parameters. From the home page, choose "Advanced Search"; on the search page, choose "X-ray cell dimensions" from the dropdown list of query types. > >Performing this search finds 12 structures in the PDB with c axis > 600 A and a and b axes < 100 A. Two of these are fiber diffraction molecular envelopes, but the other 10 are well-refined crystal structures at reasonable resolutions. So it can be done! > >- Matt > > >-- >Matthew Franklin , Ph.D. >Senior Scientist, ImClone Systems, >a wholly owned subsidiary of Eli Lilly & Company >180 Varick Street, 6th floor >New York, NY 10014 >phone:(917)606-4116 fax:(212)645-2054 > > >> -----Original Message----- >> From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of >> Christian Strube >> Sent: Tuesday, August 03, 2010 7:46 AM >> To: CCP4BB@JISCMAIL.AC.UK >> Subject: [ccp4bb] Extremely long c-axis...reasonable? >> >> Hi everybody, >> >> indexing of recently collected data gave me unit cell parameters of >> a=b= 88 and an extremely long c-axis of 652 A. My question is, if the >> value of the c-axis can be reasonable? Or am I wrong with the SG? I >> know that length doesn't count, but does anybody has a longer one? Is >> there a function in the pdb to look for the length of axes? >> >> Thanks, >> >> Christian >> >> Helmholtz-Zentrum f?r Infektionsforschung GmbH | Inhoffenstra?e 7 | >> 38124 Braunschweig | www.helmholtz-hzi.de >> >> Vorsitzende des Aufsichtsrates: MinDir'in B?rbel Brumme- Bothe, >> Bundesministerium f?r Bildung und Forschung >> Stellvertreter: MinDirig Heiko Gevers, Nieders?chsisches Ministerium >> f?r Wissenschaft und Kultur >> Gesch?ftsf?hrung: Prof. Dr. J?rgen Wehland; Ulf Richter, MBA >> Gesellschaft mit beschr?nkter Haftung (GmbH) >> Sitz der Gesellschaft: Braunschweig >> Handelsregister: Amtsgericht Braunschweig, HRB 477 >Confidentiality Note: >This e-mail, and any attachment to it, contains privileged and confidential information intended only for the use of the individual(s) or entity named on the e-mail. If the reader of this e-mail is not the intended recipient, or the employee or agent responsible for delivering it to the intended recipient, you are hereby notified that reading it is strictly prohibited. If you have received this e-mail in error, please immediately return it to the sender and delete it from your system. > >Thank you. Phoebe A. Rice Assoc. Prof., Dept. of Biochemistry & Molecular Biology The University of Chicago phone 773 834 1723 http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123 RNA is really nifty DNA is over fifty We have put them both in one book Please do take a really good look http://www.rsc.org/shop/books/2008/9780854042722.asp
