Symmetry and space groups: Difference between revisions
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There are 230 space groups, 65 of which accessible to proteins. | There are 230 space groups, 65 of which accessible to proteins. | ||
Empirically, P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub> is the space group which occurs most often (23%) in the [http://www.rcsb.org PDB]; second place is | Empirically, P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub> is the space group which occurs most often (23%) in the [http://www.rcsb.org PDB]; second place is P2<sub>1</sub> with 14.4%, then comes C2 (9.0%) ( [http://www.rcsb.org/pdb/statistics/histogram.do?mdcat=symmetry&mditem=space_group_name_H-M&numOfbars=200]). | ||
== Reflection conditions == | == Reflection conditions == | ||
These are explained and listed in Section 2.2.13 of International Tables of Crystallography, Volume A . If this is not on your desk, check out the IUCr wiki: | These are explained and listed in Section 2.2.13 of International Tables of Crystallography, Volume A . If this is not on your desk, check out the [http://reference.iucr.org/dictionary/Main_Page IUCr wiki]: | ||
[[iucr:Reflection_conditions|Reflection_conditions]] which explains the topic, and links to lists of the general absences in article [[iucr:Integral_reflection_conditions| | [[iucr:Reflection_conditions|Reflection_conditions]] which explains the topic, and links to lists of the general absences in article [[iucr:Integral_reflection_conditions|integral reflection conditions]], and the absences along the screw axes in [[iucr:Serial_reflection_conditions|serial reflection conditions]]. | ||
Latest revision as of 19:33, 11 May 2008
Space group operators can be found here: http://www.embl-hamburg.de/~pinotsis/spacegroup.html
The crystallographic toolbox is at [1]. Its predecessor, SgInfo, is here.
Facts about space groups[edit | edit source]
There are 230 space groups, 65 of which accessible to proteins.
Empirically, P212121 is the space group which occurs most often (23%) in the PDB; second place is P21 with 14.4%, then comes C2 (9.0%) ( [2]).
Reflection conditions[edit | edit source]
These are explained and listed in Section 2.2.13 of International Tables of Crystallography, Volume A . If this is not on your desk, check out the IUCr wiki:
Reflection_conditions which explains the topic, and links to lists of the general absences in article integral reflection conditions, and the absences along the screw axes in serial reflection conditions.