Structure, salt-bridge’s energetics and microenvironments of nucleoside diphosphate kinase from halophilic, thermophilic and mesophilic microbes

The fundamental principle that maintains the stability of homologous proteins, operating under diverse environmental conditions, is not fully clear. Here, we studied Nucleosdie Diphosphate Kinase (NDK) from halophilic (hNDK) and thermophilic (tNDK) archaea in reference to mesophilic (mNDK) bacteria. Results show that relative to mNDK, salt-bridge partners and its energetics is more preferred in hNDK and tNDK. Notably, the intrinsic microenvironment (MIE) features also play a prominent role in the latter cases.