It is out of principle misleading to think of the Matthews coefficient as one hard number. Xinghua mentions it actually: 'with 87 % confidence' (although 'confidence as in confidence interval' is a statistically too hard term here imho). The Matthews probability calculator gives a more complete picture of the probable values and their distribution. http://www.ruppweb.org/mattprob/default.html
BR -----Original Message----- From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of Christian Biertuempfel Sent: Friday, June 25, 2010 9:34 AM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Matthews coefficient Dear Xinghua, Of course, you can have 2 molecules in the asu. However, if things don't it is worth to double-check your space group or check for twinning. Cheers christian xinghua qin wrote: > hi CCPeers > The Matthews coefficient of my protein is 3 calculated with > matthews-cell content analysis CCP4 programe with 87% confidence , but > when doing the refinement the third molecular couldn't get into the unit > cell because of too many clashes.Deletion of the clashed AA did not > work well, Then I used two molecules in the unit cell, After refining > with Refmac, I found that the R factor is 0.29, R free is 0.40.I believe > the value can be better with the real space refinement.But the question > is that can the calculated Matthews coefficient be wrong? > > Best regards > > Xinghua Qin > > -- > Xinghua Qin > College of Biological Sciences > No.2, Yuan Ming Yuan West Road > Haidian District,Beijing,China,100094 > Tel: +86-10-62732672 -- _______________________________________________________________________ Dr. Christian Biert�mpfel Laboratory of Molecular Biology NIDDK/National Institutes of Health phone: +1 301 402 4647 9000 Rockville Pike, Bldg. 5, Rm. B1-03 fax: +1 301 496 0201 Bethesda, MD 20892-0580 USA _______________________________________________________________________
