Functional characterization of the DnaK chaperone system from the archaeon Methanothermobacter thermautotrophicus ΔH

Popp, Simone L.; Reinstein, Jochen

doi:10.1016/j.febslet.2008.12.062

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Volume 583, Issue 3 , Pages 573-578, 4 February 2009

Functional characterization of the DnaK chaperone system from the archaeon Methanothermobacter thermautotrophicus ΔH

Edited by Jesus Avila

Max-Planck-Institute for Medical Research, Department of Biomolecular Mechanisms, Jahnstrasse 29, D-69120 Heidelberg, Germany

Received 30 October 2008; received in revised form 19 December 2008; accepted 30 December 2008. published online 21 January 2009.

Abstract

We characterized the biochemical and functional properties of the DnaK system from the archaeon Methanothermobacter thermautotrophicus ΔH. In contrast to the eubacterial chaperone components the archaeal Hsp70 system shows thermal transitions only slightly above the optimal environmental temperature (65°C). Nevertheless, it prevents aggregation of luciferase in the physiological temperature range of the organism, but is also fully functional at 30°C in luciferase refolding. Additionally, GrpE_M.th. and DnaJ_M.th. substitute their eubacterial counterparts whereas DnaK_M.th. is only functional with its native cochaperones which could be attributed to a functional specialization of the eubacterial chaperones during evolution.