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Science 3 March 2000: RESEARCH ARTICLE Vol. 287 no. 5458 pp. 1615-1622 The Catalytic Pathway of Cytochrome P450cam at Atomic Resolution
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Science 3 March 2000: RESEARCH ARTICLE Vol. 287 no. 5458 pp. 1615-1622 The Catalytic Pathway of Cytochrome P450cam at Atomic Resolution IlmeSchlichting, Joel Berendzen, Kelvin Chu, Ann M. Stock, Shelley A. Maves, David E. Benson, Robert M. Sweet, Dagmar Ringe, Gregory A. Petsko, Stephen G. Sligar
IPMDH: Mesophile and Thermophile Zavodszky et al., PNAS (1998)
The Paradox Hypothesis: Thermophilic enzymes are too rigid at moderate temperatures to function properly; they only exhibit the proper range of dynamics at their normally elevated temperatures
H/D exchangeat 25o C Svingor et al., J. Biol. Chem. (2001) 276, 28121-28125
H/D exchangenear temperature optimum Svingor et al., J. Biol. Chem. (2001) 276, 28121-28125
IPMDH B-factors vs residueE. coli S. typhimuriumT. thermophilus
DHFR catalyzes the reduction of DHF to THF using NADPH Mark Wilson
DHFR: Reaction, Structure and Conformations of Met20 Loop Hod, Radkiewicz and Brooks, PNAS 2003
NMR studies show protein motion that is probably important for ligand binding and product release Peter Wright
Fraser et al., PNAS 108(39): 16247-16252 (2011) We found that crystal cryocooling remodels the conformational distributions of more than 35% of side chains and eliminates packing defects necessary for functional motions. In the signaling switch protein, H-Ras, an allosteric network consistent with fluctuations detected in solution by NMR was uncovered in the room-temperature, but not the cryogenic, electron-density maps. These results expose a bias in structural databases toward smaller, overpacked, and unrealistically unique models. Monitoring room-temperature conformational ensembles by X-ray crystallography can reveal motions crucial for catalysis, ligand binding, and allosteric regulation.