Temperature dependence of the flexibility of thermophilic and mesophilic flavoenzymes of the nitroreductase fold.

ABSTRACT: A widely held hypothesis regarding the thermostability of thermophilic proteins states asserts that, at any given temperature, thermophilic proteins are more rigid than their mesophilic counterparts. Many experimental and computational studies have addressed this question with conflicting results. Here, we compare two homologous enzymes, one mesophilic (Escherichia coli FMN-dependent nitroreductase; NTR) and one thermophilic (Thermus thermophilus NADH oxidase; NOX), by multiple molecular dynamics simulations at temperatures from 5 to 100 degrees C. We find that the global rigidity/flexibility of the two proteins, assessed by a variety of metrics, is similar on the time scale of our simulations. However, the thermophilic enzyme retains its native conformation to a much greater degree at hig

SUBMITTER: Merkley ED 

PROVIDER: S-EPMC2851445 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature