, Volume 14, Issue 4, pp 409–415

Glutamate kinase from Thermotoga maritima: characterization of a thermophilic enzyme for proline biosynthesis

Original Paper

DOI: 10.1007/s00792-010-0320-9

Cite this article as:
Pérez-Arellano, I. & Cervera, J. Extremophiles (2010) 14: 409. doi:10.1007/s00792-010-0320-9


Glutamate kinase (GK), an enzyme involved in osmoprotection in plants and microorganisms, catalyses the first and controlling step of proline biosynthesis. The proB gene encoding GK was cloned from the hyperthermophilic bacterium Thermotoga maritima and overexpressed in Escherichia coli, and the resulting protein was purified to homogeneity in three simple steps. T. maritima GK behaved as a tetramer, showing maximal activity at 83°C, and was inhibited by ADP and proline. Although T. maritima GK exhibited high amino acid similarity to the mesophilic E. coli GK, it was less dependent of Mg ions and was not aggregated in the presence of proline. Moreover, it displayed a greater thermostability and higher catalytic efficiency than its mesophilic counterpart at elevated temperatures.


Amino acid kinase familyPUA domainproBThermophilic enzymeProline inhibition



Thermotoga maritima glutamate kinase


Escherichia coli glutamate kinase

Copyright information

© Springer 2010

Authors and Affiliations

  1. 1.Centro de Investigación Príncipe Felipe (CIPF), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII)ValenciaSpain