Tehei M, Franzetti B, Madern D, Ginzburg M, Ginzburg BZ, Giudici-Orticoni MT, Bruschi M, Zaccai G. Adaptation to extreme environments: macromolecular dynamics in bacteria compared in vivo by neutron scattering.
EMBO Rep 2004;
5:66-70. [PMID:
14710189 PMCID:
PMC1298960 DOI:
10.1038/sj.embor.7400049]
[Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2003] [Revised: 09/29/2003] [Accepted: 10/13/2003] [Indexed: 11/09/2022] Open
Abstract
Mean macromolecular dynamics was quantified in vivo by neutron scattering in psychrophile, mesophile, thermophile and hyperthermophile bacteria. Root mean square atomic fluctuation amplitudes determining macromolecular flexibility were found to be similar for each organism at its physiological temperature ( approximately 1 A in the 0.1 ns timescale). Effective force constants determining the mean macromolecular resilience were found to increase with physiological temperature from 0.2 N/m for the psychrophiles, which grow at 4 degrees C, to 0.6 N/m for the hyperthermophiles (85 degrees C), indicating that the increase in stabilization free energy is dominated by enthalpic rather than entropic terms. Larger resilience allows macromolecular stability at high temperatures, while maintaining flexibility within acceptable limits for biological activity.
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