The minimum crystal size needed for a complete diffraction data set.
In this work, classic intensity formulae were united with an empirical spot-fading model in order to calculate the diameter of a spherical crystal that will scatter the required number of photons per spot at a desired resolution over the radiation-damage-limited lifetime. The influences of molecular weight, solvent content, Wilson B factor, X-ray wavelength and attenuation on scattering power and dose were all included. Taking the net photon count in a spot as the only source of noise, a complete data set with a signal-to-noise ratio of 2 at 2 A resolution was predicted to be attainable from a perfect lysozyme crystal sphere 1.2 microm in diameter and two different models of photoelectron escape reduced this to 0.5 or 0.34 microm. These represent 15-fold to 700-fold less scattering power than the smallest experimentally determined crystal size to date, but the gap was shown to be consistent with the background scattering level of the relevant experiment. These results suggest that reduction of background photons and diffraction spot size on the detector are the principal paths to improving crystallographic data quality beyond current limits.
Holton
James M
JM
Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158-2330, USA. jmholton@lbl.gov
Frankel
Kenneth A
KA
D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods*; D008970:Molecular Weight; D009113:Muramidase / Q000032:analysis; D012997:Solvents / Q000737:chemistry
D012997:Solvents; D009113:Muramidase
Methods Mol Biol. 2007;364:231-54
17172769
Nature. 1960 Feb 13;185(4711):422-7
18990802
Radiat Res. 1969 Apr;38(1):7-33
5777999
Acta Crystallogr D Biol Crystallogr. 2002 Jun;58(Pt 6  No 1):899-907
12037327
J Synchrotron Radiat. 2009 Mar;16(Pt 2):152-62
19240327
Acta Crystallogr D Biol Crystallogr. 1999 Oct;55(Pt 10):1703-17
10531520
J Synchrotron Radiat. 2008 Jan;15(Pt 1):62-73
18097080
Structure. 2003 Jan;11(1):13-9
12517336
Acta Crystallogr D Biol Crystallogr. 2006 Sep;62(Pt 9):1030-8
16929104
Acta Crystallogr D Biol Crystallogr. 2004 Jun;60(Pt 6):1085-93
15159568
Nat Protoc. 2007;2(11):2728-33
18007608
Acta Crystallogr D Biol Crystallogr. 1999 Jan;55(Pt 1):247-55
10089417
Acta Crystallogr D Biol Crystallogr. 2008 Feb;64(Pt 2):158-66
18219115
Nature. 2007 Mar 1;446(7131):97-101
17330045
Methods Enzymol. 1997;277:306-19
9379924
Acta Crystallogr D Biol Crystallogr. 1994 May 1;50(Pt 3):276-82
15299439
J Synchrotron Radiat. 2008 Sep;15(Pt 5):458-62
18728316
J Synchrotron Radiat. 2005 May;12(Pt 3):299-303
15840914
Acta Crystallogr D Biol Crystallogr. 1997 May 1;53(Pt 3):240-55
15299926
Radiat Prot Dosimetry. 2006;121(3):252-6
16603605
Acta Crystallogr D Biol Crystallogr. 2006 Feb;62(Pt 2):125-32
16421442
Biophys J. 2000 Jun;78(6):3178-85
10827994
Nature. 2007 May 24;447(7143):453-7
17468747
Nature. 2005 Jun 9;435(7043):773-8
15944695
J Synchrotron Radiat. 2002 Jul 1;9(Pt 4):198-201
12091725
Acta Crystallogr D Biol Crystallogr. 2005 Jul;61(Pt 7):850-5
15983406
J Mol Biol. 2007 Oct 5;372(5):1179-88
17825322
Phys Med Biol. 2006 Jul 7;51(13):R245-62
16790906
J Synchrotron Radiat. 2009 Mar;16(Pt 2):143-51
19240326
Methods Enzymol. 2003;368:268-88
14674279
Methods Mol Biol. 2008;426:419-35
18542881
J Synchrotron Radiat. 2009 May;16(Pt 3):368-75
19395800
J Mol Biol. 2004 Nov 5;343(5):1409-38
15491621
Protein Sci. 2003 Sep;12(9):1865-71
12930986
J Synchrotron Radiat. 2005 May;12(Pt 3):268-75
15840910
Acta Crystallogr D Biol Crystallogr. 1999 Oct;55(Pt 10):1718-25
10531521
Proc Natl Acad Sci U S A. 2006 Mar 28;103(13):4912-7
16549763
Acta Crystallogr D Biol Crystallogr. 2006 Jan;62(Pt 1):48-57
16369093
Methods Enzymol. 2003;374:300-21
14696379
Radiat Res. 1993 Nov;136(2):147-70
8248472
J Electron Spectros Relat Phenomena. 2009 Mar 1;170(1-3):4-12
20463854
Phys Med. 2009 Sep;25(3):111-21
18722148
Biophys J. 2003 Jul;85(1):451-8
12829500
J Synchrotron Radiat. 2003 Jan 1;10(Pt 1):23-5
12511787
J Synchrotron Radiat. 2007 Jan;14(Pt 1):1-3
17211066
J Synchrotron Radiat. 2000 Sep 1;7(Pt 5):313-7
16609214
Appl Radiat Isot. 2000 Oct;53(4-5):857-61
11003531
Acta Crystallogr D Biol Crystallogr. 1994 Nov 1;50(Pt 6):874-7
15299355
J Mol Biol. 1968 Apr 28;33(2):491-7
5700707
Med Phys. 2002 May;29(5):835-47
12033580
Radiat Prot Dosimetry. 2005;116(1-4 Pt 2):631-5
16604715