[ccp4bb]: Twinning/Merging

[Daniel Schlieper <Daniel.Schlieper@Uni-Koeln.DE>]

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Dear all,

Of one protein, I used 3 crystals to collect a data set at room
temperature. The data set is to 96 % complete, diffracts to 2.35 A,
and has a very high Rmerge value after scalepack: 16 % (77 % in the
2.38-2.35 A shell). 

The twinning test (from Yeates, www.doe-mbi.ucla.edu/Services/Twinning/) 
gave no twinning at all.

I used the very same protein to grow crystals of the very same crystal
form. (The crystals differ in the substrate co-crystallized). These
crystals were measured at 100 K, and I collected full data sets of
every crystal. Tested for twinning, it came true, that all of them
were twins of 5-15% (P3221, (-h,-k,l)).

Now I wonder if the 3 crystals measured at room temperature have been
twins as well, and if I may explain the high R-value with that. Is
this true?

See you in York!

Best regards, Daniel

-- 
Daniel Schlieper                      Institut fuer Biochemie
                                      Zuelpicher Strasse 47
Daniel.Schlieper@Uni-Koeln.De         Universitaet zu Koeln 
Tel.: +49 221 470-6443, Fax: -5092    50674 Koeln, Germany


-- 
Daniel Schlieper                      Institut fuer Biochemie
                                      Zuelpicher Strasse 47
Daniel.Schlieper@Uni-Koeln.De         Universitaet zu Koeln 
Tel.: +49 221 470-6443, Fax: -5092    50674 Koeln, Germany