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John Tanner wrote:
*** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.ccp4.ac.uk *** On a related issue, we found that highly conserved water molecules tend to be present in both cryo structures and room temperature ones.
That makes sense. In more general terms, we found that virtually all waters found at room temperature were also found at 100K, but half the waters that are well-defined at 100K are not observed at room temperature. So in cryo-structures we are not missing "real" waters but we haven't found a way to predict which fraction of the cryo-waters will be visible at RT. We also don't know if the extra water sites we see at 100K correspond to existing weakly bound water molecules at RT or if the reduced temperature changes the protein surface free energy landscape to such an extent that these waters have little relevance for the RT situation. We looked if the B-factors of cryogenic waters that were also present at RT was lower than for the cryo-only waters and that was not the case.
Bart -- ============================================================================== Bart Hazes (Assistant Professor) Dept. of Medical Microbiology & Immunology University of Alberta 1-15 Medical Sciences Building Edmonton, Alberta Canada, T6G 2H7 phone: 1-780-492-0042 fax: 1-780-492-7521 ==============================================================================
